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%I #5 Apr 24 2025 08:54:09
%S 1,1,9,36,169,576,2304,7396,25600,79524,250000,737881,2187441,6175225,
%T 17363889,47320641,127622209,336135556,876219201,2240128900,
%U 5666777284,14112014436,34772925625,84554753089,203576025636,484461937089,1142215875025,2665572144964,6166451098756
%N Squares of plane partition numbers.
%H Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PlanePartition.html">Plane Partition</a>
%F a(n) = [(x*y)^n] Product_{k>=1} 1 / ((1 - x^k) * (1 - y^k))^k.
%F a(n) = A000219(n)^2.
%t nmax = 28; CoefficientList[Series[Product[1/(1 - x^k)^k, {k, 1, nmax}], {x, 0, nmax}], x]^2
%Y Cf. A000219, A001255, A304990.
%K nonn
%O 0,3
%A _Ilya Gutkovskiy_, Apr 24 2025