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 A175156 #11 Dec 27 2023 00:14:05
%S A175156 1,2,4,8,6,8,8,8,0,8,4,11,4,8,9,8,7,4,4,0,1,32,9,32,26,2,24,8,36,32,
%T A175156 26,32,39,42,4,20,28,7,32,8,36,32,4,2,0,57,64,60,16,2,40,60,46,48,71,
%U A175156 50,16,8,72,32,16,32,64,8,16,32,24,35,24
%N A175156 a(n) = 2^(n-1) mod composite(n).
%o A175156 (PARI) lista(nn) = {compo = select(n->(! isprime(n) && (n != 1)), vector(nn, i, i)); for (i = 1, #compo, print1(2^(i-1) % compo[i], ", "););} \\ _Michel Marcus_, Sep 11 2013
%Y A175156 Cf. A000079, A002808, A175036, A175131.
%K A175156 nonn
%O A175156 1,2
%A A175156 _Juri-Stepan Gerasimov_, Dec 02 2010
%E A175156 More terms from _Michel Marcus_, Sep 11 2013