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 A249424 #7 Nov 02 2014 18:13:21 %S A249424 3,5,9,13,21,23,25,33,37,45,57,61,73,81,85,93,105,117,121,133,141,145, %T A249424 157,165,177,193,201,205,213,217,225,253,261,273,277,297,301,313,325, %U A249424 333,345,357,361,381,385,393,397,421,445,453,457,465,477,481,501,513,525,537,541,553,561,565,585,613,621,625,633,661,673,693,697 %N A249424 Odd integers n such that A249151(n) = (n-1)/2. %H A249424 Antti Karttunen, <a href="/A249424/b249424.txt">Table of n, a(n) for n = 1..310</a> %o A249424 (Scheme, with _Antti Karttunen_'s IntSeq-library) %o A249424 (define A249424 (MATCHING-POS 1 0 (lambda (n) (and (odd? n) (= (/ (- n 1) 2) (A249151 n)))))) %Y A249424 A249428 gives the corresponding values (n-1)/2. %Y A249424 Subsequence of A249433. %Y A249424 Cf. A249151, A249423, A249425, A249427. %K A249424 nonn %O A249424 1,1 %A A249424 _Antti Karttunen_, Oct 28 2014