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 A112881 #16 Feb 16 2025 08:32:59 %S A112881 2,3,4,5,6,7,10,12,20,21,24,34,38,75,122,166,236,355,356,930,1042, %T A112881 1214,1461,1622,4430,5802,9092,16260,18926,23698,40059,45003,73807, %U A112881 91405,263226,316872,321874,324098,581132,939189,1034005,1430138 %N A112881 Indices of prime Perrin numbers; values of n such that A001608(n) is prime. %H A112881 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PerrinSequence.html">Perrin Sequence</a> %H A112881 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/IntegerSequencePrimes.html">Integer Sequence Primes</a> %Y A112881 Cf. A001608, A074788. %K A112881 nonn,more %O A112881 1,1 %A A112881 _Eric W. Weisstein_, Oct 05 2005 %E A112881 a(34) from _Eric W. Weisstein_, Oct 06 2005 %E A112881 a(35) = 263226 from _Eric W. Weisstein_, May 04 2006 %E A112881 a(36) = 316872 from _Eric W. Weisstein_, Feb 04 2007 %E A112881 a(37) = 321874 from _Eric W. Weisstein_, Feb 19 2007 %E A112881 a(38) = 324098 from _Eric W. Weisstein_, Feb 25 2007 %E A112881 a(39) = 581132 from _Eric W. Weisstein_, Feb 15 2011 %E A112881 a(40)-a(42) from _Ryan Propper_, Jun 19 2022