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 A014420 #19 Jul 02 2014 17:01:32 %S A014420 0,1,1,2,2,1,2,2,3,3,2,3,3,4,1,2,2,3,3,2,3,3,4,4,3,4,4,5,2,3,3,4,4,3, %T A014420 4,4,5,5,4,5,5,6,1,2,2,3,3,2,3,3,4,4,3,4,4,5,2,3,3,4,4,3,4,4,5,5,4,5, %U A014420 5,6,3,4,4,5,5,4,5,5,6,6,5,6,6,7,2,3,3,4,4,3,4,4,5,5,4,5,5,6,3 %N A014420 Minimal number of Catalan numbers that sum to n. %H A014420 Olivier Gérard (first 1001 terms) & Antti Karttunen, <a href="/A014420/b014420.txt">Table of n, a(n) for n = 0..16796</a> %F A014420 a(0) = 0, a(n) = 1 + a(n-A081290(n)). - _Antti Karttunen_, Jul 02 2014 %o A014420 (Scheme, with memoization macro definec from Antti Karttunen's IntSeq-library) %o A014420 (definec (A014420 n) (if (zero? n) n (+ 1 (A014420 (- n (A081290 n)))))) %o A014420 ;; Other version, requiring A014418raw given in A014418: %o A014420 (define (A014420 n) (apply + (A014418raw n))) %o A014420 ;; _Antti Karttunen_, Jul 02 2014 %Y A014420 Cf. A014418, A081290, A244320, A244318, A244232, A236855, A236859. %K A014420 nonn,easy %O A014420 0,4 %A A014420 _Olivier Gérard_