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A292128 Expansion of Product_{k>=1} (1 - 3*x^k). 3
1, -3, -3, 6, 6, 15, -12, -3, -30, -48, 6, -12, 15, 78, 186, -21, 168, 42, 42, -246, -408, -156, -399, -552, -498, -246, 213, 1248, -318, 1608, 1392, 2508, 1482, 2976, -480, -1011, 1500, -1704, -4296, -4206, -8499, -8652, -7626, -7050, -192, -13008, -480, -2118 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Seiichi Manyama, Table of n, a(n) for n = 0..10000

FORMULA

G.f.: Sum_{i>=0} (-3)^i*x^(i*(i+1)/2)/Product_{j=1..i} (1 - x^j). - Ilya Gutkovskiy, Apr 13 2018

PROG

(PARI) N=66; x='x+O('x^N); Vec(prod(n=1, N, 1-3*x^n))

CROSSREFS

Column k=3 of A292131.

Product_{k>=1} (1 - m*x^k): A010815 (m=1), A070877 (m=2), this sequence (m=3).

Cf. A032308, A242587, A292130.

Sequence in context: A240204 A200905 A280510 * A117775 A243307 A021301

Adjacent sequences:  A292125 A292126 A292127 * A292129 A292130 A292131

KEYWORD

sign

AUTHOR

Seiichi Manyama, Sep 09 2017

STATUS

approved

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Last modified November 22 03:20 EST 2019. Contains 329383 sequences. (Running on oeis4.)