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 A261646 #7 Aug 31 2015 21:37:32 %S A261646 1,1,1,3,5,7,15,27,49,90,171,326,613,1174,2255,4333,8386,16213,31457, %T A261646 61097,118577,230322,447767,870570,1693887,3297343,6423347,12523562, %U A261646 24435171,47707012,93215393,182260604,356622869,698284551,1368195878,2682527954,5262729874,10330704931 %N A261646 Row lengths in A261644. %C A261646 First differences of A261396; %C A261646 also row lengths in A261712. %F A261646 a(n) = A261396(n) - A261396(n-1). %o A261646 (Haskell) %o A261646 a261646 = length . a261644_row %Y A261646 Cf. A261644, A261712, A261396. %K A261646 nonn %O A261646 1,4 %A A261646 _Reinhard Zumkeller_, Aug 31 2015 %E A261646 a(21)-a(38) from _Chai Wah Wu_, Aug 31 2015