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 A321567 Expansion of Product_{1 <= i_1 <= i_2 <= i_3 <= i_4} (1 + x^(i_1*i_2*i_3*i_4)). 3
 1, 1, 1, 2, 3, 4, 6, 8, 11, 16, 21, 27, 38, 49, 63, 84, 109, 138, 180, 228, 289, 369, 463, 578, 732, 911, 1128, 1407, 1741, 2140, 2646, 3243, 3967, 4861, 5924, 7196, 8767, 10616, 12827, 15516, 18707, 22486, 27054, 32440, 38835, 46488, 55502, 66136, 78836, 93727, 111265 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,4 LINKS Seiichi Manyama, Table of n, a(n) for n = 0..10000 FORMULA G.f.: Product_{k>0} (1 + x^k)^A218320(k). CROSSREFS Product_{1 <= i_1 <= i_2 <= ... <= i_b} (1 + x^(i_1 * i_2 * ... * i_b)): A000009 (b=1), A211856 (b=2), A321359 (b=3), this sequence (b=4). Cf. A066806, A218320, A321566. Sequence in context: A289432 A064660 A321359 * A066806 A271486 A226187 Adjacent sequences:  A321564 A321565 A321566 * A321568 A321569 A321570 KEYWORD nonn AUTHOR Seiichi Manyama, Nov 13 2018 STATUS approved

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Last modified August 7 23:50 EDT 2022. Contains 355995 sequences. (Running on oeis4.)