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 A266420 #6 Jan 30 2016 03:10:56 %S A266420 5,11,17,19,23,27,29,35,39,41,45,47,53,55,57,59,61,65,71,77,81,83,85, %T A266420 89,91,95,97,101,103,107,109,113,117,119,121,123,125,131,137,139,143, %U A266420 145,147,149,153,155,157,161,165,167,173,175,177,179,181,183,185,187,191,197,199,203,207,209,213,215,217,221,225 %N A266420 Odd unlucky numbers. %H A266420 Antti Karttunen, <a href="/A266420/b266420.txt">Table of n, a(n) for n = 1..10000</a> %o A266420 (Scheme, with _Antti Karttunen_'s IntSeq-library) %o A266420 (define A266420 (MATCHING-POS 1 1 (lambda (n) (and (odd? n) (zero? (A145649 n)))))) %Y A266420 Intersection of A005408 and A050505. %Y A266420 Cf. A145649, A257726. %Y A266420 Cf. also A071904, A266419 %K A266420 nonn %O A266420 1,1 %A A266420 _Antti Karttunen_, Jan 28 2016