According to Wikipedia,
In mathematics, a natural number \$n\$ is a Blum integer if \$n = p \times q\$ is a semiprime for which \$p\$ and \$q\$ are distinct prime numbers congruent to \$3 \bmod 4\$. That is, \$p\$ and \$q\$ must be of the form \$4t + 3\$, for some integer \$t\$. Integers of this form are referred to as Blum primes. This means that the factors of a Blum integer are Gaussian primes with no imaginary part.
The first few Blum integers are:
21, 33, 57, 69, 77, 93, 129, 133, 141, 161, 177, 201, 209, 213, 217, 237, 249, 253, 301, 309, 321, 329, 341, 381, 393, 413, 417, 437, 453, 469, 473, 489, 497, 501, 517, 537, 553, 573, 581, 589, 597, 633, 649, 669, 681, 713, 717, 721, 737, 749, 753, 781, 789
This is OEIS A016105
Your task is to make a program that does one of the following:
- Take an index \$n\$ and output the \$n^{th}\$ Blum integer, either 0 or 1 indexing.
- Take a positive integer \$n\$ and output the first \$n\$ Blum integers.
- Output all Blum integers infinitely.
This is code-golf so shortest answer wins.