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 A235043 #6 Jan 16 2014 15:04:33 %S A235043 0,0,0,0,0,1,1,1,1,1,1,1,1,1,1,1,1,2,2,2,2,2,2,3,3,3,3,3,3,4,4,4,4,4, %T A235043 4,4,4,4,4,4,4,4,4,5,5,5,5,5,5,5,5,5,5,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6, %U A235043 6,6,6,7,7,7,7,7,7,7,7,8,8,8,8,9,9,9,9,9,9,10 %N A235043 Partial sums of the characteristic function of A091209. %C A235043 Note that this also works as an inverse function of A091209 in a sense that a(A091209(n)) = n for all n>=1. %H A235043 Antti Karttunen, <a href="/A235043/b235043.txt">Table of n, a(n) for n = 0..10007</a> %o A235043 (Scheme) %o A235043 (define (A235043 n) (if (zero? n) n (+ (A235043 (- n 1)) (+ (* (A010051 n) (A091247 n)))))) %Y A235043 Used to compute A235041. Cf. A010051, A091247, A235044. %K A235043 nonn %O A235043 0,18 %A A235043 _Antti Karttunen_, Jan 02 2014