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 A176902 #6 Dec 05 2019 21:00:35 %S A176902 2,17,19,29,31,41,43,53,67,71,79,89,97,101,103,109,113,127,131,137, %T A176902 139,149,151,163,173,181,191,197,199,211,223,229,233,239,241,251,257, %U A176902 269,271,281,283,293,307,311,317,331,337,349,353,367,373,379,389,401,409 %N A176902 Primes p such that p-1 and p+1 are both non-semiprime. %C A176902 2 together with A060254. %F A176902 a(n+1)=A060254(n)=A167915(n+1). %e A176902 a(1)=2 because 2-1=1=non-semiprime and 2+1=3=non-semiprime. %K A176902 nonn %O A176902 1,1 %A A176902 _Juri-Stepan Gerasimov_, Apr 28 2010 %E A176902 Corrected (233, 239 inserted, 279 and 289 replaced by 379 and 389) by _R. J. Mathar_, Aug 12 2010