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 A244990 #11 Jul 23 2014 10:21:17 %S A244990 1,3,6,7,9,12,13,14,18,19,21,24,26,27,28,29,35,36,37,38,39,42,43,48, %T A244990 49,52,53,54,56,57,58,61,63,65,70,71,72,74,76,78,79,81,84,86,87,89,91, %U A244990 95,96,98,101,104,105,106,107,108,111,112,113,114,116,117,122,126,129,130,131,133,139,140,142,143,144 %N A244990 After 1, numbers whose greatest prime factor is a prime with an even index; n such that A061395(n) is even. %C A244990 Equally, after 1, natural numbers n such that A006530(n) is in A031215. %C A244990 A122111 maps each one of these numbers to a unique term of A028260 and vice versa. %H A244990 Antti Karttunen, <a href="/A244990/b244990.txt">Table of n, a(n) for n = 1..10001</a> %F A244990 For all n, A244988(a(n)) = n. %o A244990 (Scheme, with _Antti Karttunen_'s IntSeq-library) %o A244990 (define A244990 (MATCHING-POS 1 1 (COMPOSE even? A061395))) %Y A244990 Complement: A244991. %Y A244990 Cf. A006530, A028260, A031215, A061395, A122111, A244988, A244321, A244322. %K A244990 nonn %O A244990 1,2 %A A244990 _Antti Karttunen_, Jul 21 2014