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%I #7 Jan 27 2024 10:30:30
%S 1,1,2,5,13,33,81,194,458,1074,2513,5876,13722,31961,74168,171395,
%T 394450,904393,2066770,4709538,10704306,24273709,54926658,124036675,
%U 279559571,628906790,1412254773,3165780760,7084607367,15828666526,35309625162,78648201835,174927430681
%N Expansion of Product_{j=1..n, k=1..n} (1 + x^(k^j)).
%H Vaclav Kotesovec, <a href="/A369578/b369578.txt">Table of n, a(n) for n = 0..1000</a>
%t Table[SeriesCoefficient[Product[Product[1 + x^(k^j), {k, 1, n^(1/j)}], {j, 1, n}], {x, 0, n}], {n, 0, 40}]
%Y Cf. A000009, A033461, A279329, A369575, A369570.
%K nonn
%O 0,3
%A _Vaclav Kotesovec_, Jan 26 2024