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%I #6 Mar 31 2012 14:42:50
%S 0,0,0,0,19,32,24,67,89,38,71,173,69,61,71,109,373,211,79,529,587,72,
%T 89,779,283,461,499,359,1159,311,111,1423,1517,269,857,1817,641,127,
%U 134,251,2377,1249,138,2749,2879,251,787,173,381,1787,1861,1291
%N a(n) = smallest k such that A000326(n+1) = A000326(n) + (A000326(n) mod k), or 0 if no such k exists.
%C a(n) is the "weight" of pentagonal numbers (A000326).
%C The decomposition of pentagonal numbers into weight * level + gap is A000326(n) = a(n) * A184751(n) + A016777(n) if a(n) > 0.
%H Remi Eismann, <a href="/A133151/b133151.txt">Table of n, a(n) for n = 1..1000</a>
%e For n = 1 we have A000326(n) = 1, A000326(n+1) = 5; there is no k such that 5 - 1 = 4 = (1 mod k), hence a(1) = 0.
%e For n = 5 we have A000326(n) = 35, A000326(n+1) = 51; 19 is the smallest k such that 51 - 35 = 16 = (35 mod k), hence a(5) = 19.
%e For n = 18 we have A000326(n) = 477, A000326(n+1) = 532; 211 is the smallest k such that 532 - 477 = 55 = (477 mod k), hence a(18) = 211.
%Y Cf. A000326, A016777, A184751, A184750, A117078, A117563, A001223, A118534.
%K nonn
%O 1,5
%A _Rémi Eismann_, Sep 22 2007 - Jan 21 2011
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