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Clarified you can return the first n terms, instead of just the nth one.
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Another sequence, another challenge.*

Definition

A prime p is in this sequence, let's call it A, iff for every digit d in p's decimal expansion, you replace d with d copies of d and the resulting integer is still prime; zeros are not permitted.

For example, 11 is trivially in this sequence (it's the first number, incidentally). Next in the sequence is 31, because 3331 is also prime; then 53 because 55555333 is also prime, and so on.

Challenge

Given an input n, return A(n), i.e. the nth item in this sequence.

Examples

Here are the first 20 terms to get you started. This is A057628 on OEIS.

11, 31, 53, 131, 149, 223, 283, 311, 313, 331, 397, 463, 641, 691, 937, 941, 1439, 1511, 1741, 1871

This means A(0) = 11, A(1) = 31, etc., when using zero indexing.

Rules

  • You can choose zero- or one-based indexing; please specify in your answer which.
  • Instead of returning just the nth element, you can instead choose to return the first n terms.
  • You can assume that the input/output will not be larger than your language's native integer format; however, the repeated-digit prime may be larger than your language's native format, so that will need to be accounted for.
  • For example, 1871, the last number of the examples, has a corresponding prime of 18888888877777771, which is quite a bit larger than standard INT32.
  • Either a full program or a function are acceptable. If a function, you can return the output rather than printing it.
  • Output can be to the console, returned from a function, displayed in an alert popup, etc.
  • Standard loopholes are forbidden.
  • This is so all usual golfing rules apply, and the shortest code (in bytes) wins.

*To be fair, I had come up with the first few terms of the sequence just playing around with some numbers, and then went to OEIS to get the rest of the sequence.

Another sequence, another challenge.*

Definition

A prime p is in this sequence, let's call it A, iff for every digit d in p's decimal expansion, you replace d with d copies of d and the resulting integer is still prime; zeros are not permitted.

For example, 11 is trivially in this sequence (it's the first number, incidentally). Next in the sequence is 31, because 3331 is also prime; then 53 because 55555333 is also prime, and so on.

Challenge

Given an input n, return A(n), i.e. the nth item in this sequence.

Examples

Here are the first 20 terms to get you started. This is A057628 on OEIS.

11, 31, 53, 131, 149, 223, 283, 311, 313, 331, 397, 463, 641, 691, 937, 941, 1439, 1511, 1741, 1871

This means A(0) = 11, A(1) = 31, etc., when using zero indexing.

Rules

  • You can choose zero- or one-based indexing; please specify in your answer which.
  • You can assume that the input/output will not be larger than your language's native integer format; however, the repeated-digit prime may be larger than your language's native format, so that will need to be accounted for.
  • For example, 1871, the last number of the examples, has a corresponding prime of 18888888877777771, which is quite a bit larger than standard INT32.
  • Either a full program or a function are acceptable. If a function, you can return the output rather than printing it.
  • Output can be to the console, returned from a function, displayed in an alert popup, etc.
  • Standard loopholes are forbidden.
  • This is so all usual golfing rules apply, and the shortest code (in bytes) wins.

*To be fair, I had come up with the first few terms of the sequence just playing around with some numbers, and then went to OEIS to get the rest of the sequence.

Another sequence, another challenge.*

Definition

A prime p is in this sequence, let's call it A, iff for every digit d in p's decimal expansion, you replace d with d copies of d and the resulting integer is still prime; zeros are not permitted.

For example, 11 is trivially in this sequence (it's the first number, incidentally). Next in the sequence is 31, because 3331 is also prime; then 53 because 55555333 is also prime, and so on.

Challenge

Given an input n, return A(n), i.e. the nth item in this sequence.

Examples

Here are the first 20 terms to get you started. This is A057628 on OEIS.

11, 31, 53, 131, 149, 223, 283, 311, 313, 331, 397, 463, 641, 691, 937, 941, 1439, 1511, 1741, 1871

This means A(0) = 11, A(1) = 31, etc., when using zero indexing.

Rules

  • You can choose zero- or one-based indexing; please specify in your answer which.
  • Instead of returning just the nth element, you can instead choose to return the first n terms.
  • You can assume that the input/output will not be larger than your language's native integer format; however, the repeated-digit prime may be larger than your language's native format, so that will need to be accounted for.
  • For example, 1871, the last number of the examples, has a corresponding prime of 18888888877777771, which is quite a bit larger than standard INT32.
  • Either a full program or a function are acceptable. If a function, you can return the output rather than printing it.
  • Output can be to the console, returned from a function, displayed in an alert popup, etc.
  • Standard loopholes are forbidden.
  • This is so all usual golfing rules apply, and the shortest code (in bytes) wins.

*To be fair, I had come up with the first few terms of the sequence just playing around with some numbers, and then went to OEIS to get the rest of the sequence.

Source Link
AdmBorkBork
AdmBorkBork
  • 43.5k
  • 5
  • 103
  • 284

Repeated Digit Primes

Another sequence, another challenge.*

Definition

A prime p is in this sequence, let's call it A, iff for every digit d in p's decimal expansion, you replace d with d copies of d and the resulting integer is still prime; zeros are not permitted.

For example, 11 is trivially in this sequence (it's the first number, incidentally). Next in the sequence is 31, because 3331 is also prime; then 53 because 55555333 is also prime, and so on.

Challenge

Given an input n, return A(n), i.e. the nth item in this sequence.

Examples

Here are the first 20 terms to get you started. This is A057628 on OEIS.

11, 31, 53, 131, 149, 223, 283, 311, 313, 331, 397, 463, 641, 691, 937, 941, 1439, 1511, 1741, 1871

This means A(0) = 11, A(1) = 31, etc., when using zero indexing.

Rules

  • You can choose zero- or one-based indexing; please specify in your answer which.
  • You can assume that the input/output will not be larger than your language's native integer format; however, the repeated-digit prime may be larger than your language's native format, so that will need to be accounted for.
  • For example, 1871, the last number of the examples, has a corresponding prime of 18888888877777771, which is quite a bit larger than standard INT32.
  • Either a full program or a function are acceptable. If a function, you can return the output rather than printing it.
  • Output can be to the console, returned from a function, displayed in an alert popup, etc.
  • Standard loopholes are forbidden.
  • This is so all usual golfing rules apply, and the shortest code (in bytes) wins.

*To be fair, I had come up with the first few terms of the sequence just playing around with some numbers, and then went to OEIS to get the rest of the sequence.