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 A262521 #5 Oct 03 2015 08:43:54 %S A262521 112,113,544,545,684,760,930,1306,1514,1522,1624,1625,2048,2386,2389, %T A262521 2393,2399,2402,2818,2827,2966,2969,3280,3281,3791,3797,3878,4324, %U A262521 4326,4328,4330,4331,4333,4334,4336,4340,4342,4346,4352,5513,5515,5519,5521,5527,5531,5724,5726,6050,6161,6165,6167,6168,6169,6172,6173,6176,6177,6179,6181,6183,6184,6185,6272 %N A262521 Numbers where A262520 takes a negative value; numbers n for which A155043(2n) > A155043(2n + 1). %H A262521 Antti Karttunen, <a href="/A262521/b262521.txt">Table of n, a(n) for n = 1..1004</a> %o A262521 (Scheme, with _Antti Karttunen_'s IntSeq-library) %o A262521 (define A262521 (MATCHING-POS 1 0 (COMPOSE negative? A262520))) %Y A262521 Cf. A000005, A049820, A155043, A262518, A262519, A262520. %K A262521 nonn %O A262521 1,1 %A A262521 _Antti Karttunen_, Oct 02 2015