This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A356135 #14 Jan 24 2023 16:45:06 %S A356135 4,6,9,10,22,26,177,183,213,27662,3066886,3067021,3067161,3067166, %T A356135 3067186,3067241,3067271,3067421,3067426,3067541,3067561,3067571, %U A356135 3067586,3067661,3067681,3067711,3067741,3067901,3067906,3067991,3068041,44690978177,44690978534,44690978639,44690978891 %N A356135 Semiprimes k such that k is congruent to 6 modulo k's index in the sequence of semiprimes. %C A356135 a(42) > 8040423200947. %H A356135 Lucas A. Brown, <a href="/A356135/b356135.txt">Table of n, a(n) for n = 1..41</a> %H A356135 Lucas A. Brown, <a href="https://github.com/lucasaugustus/oeis/blob/main/semiprimemods.py">semiprimemods.py</a>. %F A356135 a(n) = A001358(A106131(n)). %e A356135 The 1st semiprime is 4, which is congruent to 6 (mod 1), so 4 is in the sequence. %e A356135 The 2nd semiprime is 6, which is congruent to 6 (mod 2), so 6 is in the sequence. %e A356135 The 3rd semiprime is 9, which is congruent to 6 (mod 3), so 9 is in the sequence. %e A356135 The 4th semiprime is 10, which is congruent to 6 (mod 4), so 10 is in the sequence. %e A356135 The 5th semiprime is 14, which is not congruent to 6 (mod 5), so 14 is not in the sequence. %Y A356135 Cf. A001358, A106131. %K A356135 nonn,hard %O A356135 1,1 %A A356135 _Lucas A. Brown_, Oct 14 2022