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%I #5 Dec 02 2020 09:01:02
%S 1,0,1,0,2,0,3,1,3,2,4,3,6,5,6,6,10,7,13,10,15,13,20,15,26,21,28,26,
%T 36,31,44,42,49,50,61,57,75,73,84,85,103,97,123,121,137,140,166,159,
%U 194,194,216,225,256,253,295,304,330,346,389,387,446,456,498,516,579,576
%N Number of partitions of n into an even number of triangular numbers.
%H <a href="/index/Par#part">Index entries for sequences related to partitions</a>
%H <a href="/index/Pol#polygonal_numbers">Index to sequences related to polygonal numbers</a>
%F G.f.: (1/2) * (Product_{k>=1} 1 / (1 - x^(k*(k + 1)/2)) + Product_{k>=1} 1 / (1 + x^(k*(k + 1)/2))).
%F a(n) = (A007294(n) + A292519(n)) / 2.
%e a(6) = 3 because we have [3, 3], [3, 1, 1, 1] and [1, 1, 1, 1, 1, 1].
%t nmax = 65; CoefficientList[Series[(1/2) (Product[1/(1 - x^(k (k + 1)/2)), {k, 1, nmax}] + Product[1/(1 + x^(k (k + 1)/2)), {k, 1, nmax}]), {x, 0, nmax}], x]
%Y Cf. A000217, A007294, A027187, A292519, A339364, A339374, A339375, A339376.
%K nonn
%O 0,5
%A _Ilya Gutkovskiy_, Dec 02 2020