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 A091982 #11 May 07 2017 10:05:35 %S A091982 1,4181,6721,13201,34561,51841,64681,90061,96049,97921,163081,186961, %T A091982 197209,268801,283361,302101,330929,399001,489601,520801,636641, %U A091982 655201,920577,999941,1034881,1072513,1081649,1084201,1106561,1317121,1346269,1392169,1533601 %N A091982 Nonprimes n such that Mod(n,4) == 1 and denominator(Fibonacci((n-1)/4)/n) = 1. %H A091982 Giovanni Resta, <a href="/A091982/b091982.txt">Table of n, a(n) for n = 1..2500</a> %t A091982 Select[Range[1, 10^6, 4], And[! PrimeQ@ #, Denominator[Fibonacci[(# - 1)/4]/#] == 1] &] (* _Michael De Vlieger_, May 07 2017 *) %Y A091982 For primes see A047272. %K A091982 nonn,easy %O A091982 1,2 %A A091982 Mohammed Bouayoun (bouyao(AT)wanadoo.fr), Mar 17 2004 %E A091982 a(16)-a(33) from _Giovanni Resta_, May 06 2017