cp's OEIS Frontend

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.

A072964 Number of partitions of n-th triangular number n(n+1)/2 (A000217(n)) into triangular parts.

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%I A072964 #14 May 21 2018 11:44:08
%S A072964 1,1,2,4,7,15,32,66,141,295,619,1286,2654,5460,11066,22357,44962,
%T A072964 89258,176459,347103,675846,1309903,2525893,4830943,9196093,17418788,
%U A072964 32772432,61375543,114401182,212026732,391231769,718710706,1313781686
%N A072964 Number of partitions of n-th triangular number n(n+1)/2 (A000217(n)) into triangular parts.
%C A072964 What is limit_{n->inf} a(n)^(1/n)? [This limit is equal to 1. - _Vaclav Kotesovec_, May 21 2018]
%H A072964 T. D. Noe, <a href="/A072964/b072964.txt">Table of n, a(n) for n=0..100</a>
%F A072964 a(n) = A007294[n(n+1)/2] = coefficient of x^[n(n+1)/2] in the expansion of product_{k=1..inf} 1/(1 - x^(k(k+1)/2)).
%F A072964 a(n) = A007294(A000217(n)).
%F A072964 a(n) ~ exp(3*Pi^(1/3) * Zeta(3/2)^(2/3) * (n*(n+1))^(1/3) / 2^(4/3)) * Zeta(3/2) / (4*Pi*sqrt(3)*n^3). - _Vaclav Kotesovec_, May 21 2018
%t A072964 c = CoefficientList[ Series[1/Product[1 - x^(i(i + 1)/2), {i, 1, 50}], {x, 0, 565}], x]; c[[Range[33]*(Range[33] + 1)/2 + 1]] (* _Robert G. Wilson v_ *)
%Y A072964 Cf. A007294, A073420, A114738.
%K A072964 nonn
%O A072964 0,3
%A A072964 _Paul D. Hanna_, Aug 13 2002
%E A072964 Entry revised by _N. J. A. Sloane_, Jan 28 2007