A356755 Semiprimes k such that k is congruent to 2 modulo k's index in the sequence of semiprimes.
4, 6, 10, 119, 155, 158, 215, 27682, 3066887, 3066907, 3067027, 3067167, 3067187, 3067247, 3067277, 3067682, 3067687, 3067742, 3067787, 3067847, 3067907, 3067917, 3067937, 3067942, 3068042, 3068067, 348933302, 348933422, 44690978131, 44690978257, 44690978537, 44690978719, 44690978971
Offset: 1
Examples
The 1st semiprime is 4, which is congruent to 2 (mod 1), so 4 is in the sequence. The 2nd semiprime is 6, which is congruent to 2 (mod 2), so 6 is in the sequence. The 3rd semiprime is 9, which is congruent to 0 (mod 3), so 9 is not in the sequence. The 4th semiprime is 10, which is congruent to 2 (mod 4), so 10 is in the sequence.
Links
- Lucas A. Brown, semiprimemods.py
Comments