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• Abundant numbers
• Fibonacci numbers - the version that returns the index
• OEIS A033286 (\$np_n)\$
• Factorial numbers
• Proth numbers
• Consecutive-prime/constant-exponent numbers
• Is the number binary-heavy?
• Euler's totient function by Grimmy
• Shift right by half a bit
• Decompose a number!

• Abundant numbers
• Fibonacci numbers - the version that returns the index
• OEIS A033286 (\$np_n)\$
• Factorial numbers
• Proth numbers
• Consecutive-prime/constant-exponent numbers
• Is the number binary-heavy?
• Euler's totient function by Grimmy
• Shift right by half a bit
• Decompose a number!
• Decide symmetry of fractions

• Abundant numbers
• Fibonacci numbers - the version that returns the index
• OEIS A033286 (\$np_n)\$
• Factorial numbers
• Proth numbers
• Consecutive-prime/constant-exponent numbers
• Is the number binary-heavy?
• Euler's totient function by Grimmy
• Shift right by half a bit
• Is it a Giuga number?
• Decompose a number!

This can be shortened further, thanks to a trick found by Grimmy (and used in this post). I've used it to shorten factorial, Proth, \$np_n\$, and consecutive-prime/constant-exponent regexes. (Giuga numbers also uses the shortened form, but cannot benefit from this trick.) As a standalone division regex, it comes in at 39 bytes:

• Abundant numbers
• Fibonacci numbers - the version that returns the index
• OEIS A033286 (\$np_n)\$
• Factorial numbers
• Proth numbers
• Consecutive-prime/constant-exponent numbers
• Is the number binary-heavy?
• Euler's totient function by Grimmy
• Shift right by half a bit
• Decompose a number!

This can be shortened further, thanks to a trick found by Grimmy (and used in this post). I've used it to shorten factorial, Proth, \$np_n\$, and consecutive-prime/constant-exponent regexes. As a standalone division regex, it comes in at 39 bytes:

This can be shortened further, thanks to a trick found by Grimmy (and used in this post). I've used it to shorten factorial, Proth, \$np_n\$, and consecutive-prime/constant-exponent regexes. As a standalone division regex, it comes in at 39 bytes:

This can be shortened further, thanks to a trick found by Grimmy (and used in this post). I've used it to shorten factorial, Proth, \$np_n\$, and consecutive-prime/constant-exponent regexes. (Giuga numbers also uses the shortened form, but cannot benefit from this trick.) As a standalone division regex, it comes in at 39 bytes: