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 A266419 #9 Jan 30 2016 03:10:46 %S A266419 9,15,19,21,27,31,33,35,39,45,49,51,55,57,59,63,65,69,73,75,79,81,85, %T A266419 87,93,95,99,101,103,105,109,111,113,117,123,125,129,133,135,137,139, %U A266419 141,145,147,151,153,155,159,163,165,167,169,171,177,183,185,187,189,191,195,197,199,201,203,205,207,213,215 %N A266419 Odd nonludic numbers. %H A266419 Antti Karttunen, <a href="/A266419/b266419.txt">Table of n, a(n) for n = 1..10220</a> %F A266419 Other identities. For all n >= 1: %F A266419 a(n) = 1 + 2*A266410(n). %o A266419 (Scheme, with _Antti Karttunen_'s IntSeq-library) %o A266419 (define A266419 (MATCHING-POS 1 1 (lambda (n) (and (odd? n) (zero? (A192490 n)))))) %Y A266419 Intersection of A005408 and A192607. %Y A266419 Cf. A192490, A266410, A237126. %Y A266419 Cf. also A071904, A266420. %K A266419 nonn %O A266419 1,1 %A A266419 _Antti Karttunen_, Jan 28 2016