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 A263278 #7 Nov 09 2015 16:15:18 %S A263278 21,8480,18162,78495,1194707,1426107,6029619,325034101 %N A263278 a(n) = length of n-th run of even terms in A259934. %H A263278 A. Karttunen, <a href="https://oeis.org/plot2a?name1=A263278&name2=A262516&tform1=untransformed&tform2=untransformed&shift=0&radiop1=ratio&drawlines=true">Ratio a(n)/A262516(n) drawn with OEIS Plot2-script</a> %F A263278 a(n) = A263277((2*n)-1). %o A263278 (Scheme) (define (A263278 n) (A263277 (+ n n -1))) %Y A263278 Bisection of A263277. %Y A263278 Cf. A259934, A262514, A262516. %Y A263278 Cf. also A263253. %K A263278 nonn,more %O A263278 1,1 %A A263278 _Antti Karttunen_, Nov 08 2015