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 A263259 #8 Nov 27 2015 00:17:41 %S A263259 1,1,2,1,2,1,3,1,2,3,4,2,5,1,3,2,3,1,4,1,4,2,5,1,2,3,4,1,5,1,6,1,3,2, %T A263259 4,1,2,1,2,2,3,1,4,1,2,2,3,2,4,3,4,1,5,1,6,2,7,1,3,1,8,1,2,2,3,1,3,1, %U A263259 3,2,4,1,4,1,3,2,4,1,5,1,6,3,4,2,4,3,4,3,5,2,6,3,4,4,5,5,5,2,4,3,6,2,5,3,7,3,5,4,8,3,6,4,7,2,7,3,8,4,4,2,7 %N A263259 a(n) = number of integers k <= n for which A155043(k) = A155043(n). %C A263259 a(n) = one-based index of n in row A155043(n) of table A263265. %H A263259 Antti Karttunen, <a href="/A263259/b263259.txt">Table of n, a(n) for n = 0..12333</a> %F A263259 Other identities. For all n >= 0: %F A263259 a(A261089(n)) = 1. %F A263259 a(A262503(n)) = A262507(n). %F A263259 A263265(A155043(n), a(n)) = n. %o A263259 (Scheme, with memoizing definec-macro) %o A263259 (definec (A263259 n) (cond ((zero? n) 1) ((= 1 (- (A263089 n) (A263089 (- n 1)))) 1) (else (let ((d (A155043 n))) (let loop ((k (- n 1))) (if (= (A155043 k) d) (+ 1 (A263259 k)) (loop (- k 1)))))))) %Y A263259 Cf. A000005, A155043, A261089, A262503, A262507, A263089, A263265, A263279. %K A263259 nonn %O A263259 0,3 %A A263259 _Antti Karttunen_, Nov 24 2015