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A307067 Expansion of 1/(2 - Product_{k>=2} (1 + x^k)). 1
1, 0, 1, 1, 2, 4, 6, 12, 19, 36, 60, 108, 187, 328, 576, 1005, 1765, 3084, 5408, 9461, 16575, 29017, 50812, 88977, 155792, 272813, 477684, 836466, 1464654, 2564685, 4490833, 7863610, 13769463, 24110774, 42218847, 73926591, 129448088, 226667986, 396903536, 694991728 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,5

COMMENTS

Invert transform of A025147.

LINKS

Table of n, a(n) for n=0..39.

FORMULA

a(0) = 1; a(n) = Sum_{k=1..n} A025147(k)*a(n-k).

MAPLE

a:=series(1/(2-mul((1+x^k), k=2..100)), x=0, 40): seq(coeff(a, x, n), n=0..39); # Paolo P. Lava, Apr 03 2019

MATHEMATICA

nmax = 39; CoefficientList[Series[1/(2 - Product[(1 + x^k), {k, 2, nmax}]), {x, 0, nmax}], x]

CROSSREFS

Cf. A025147, A055887, A299106, A304969, A307057, A317536.

Sequence in context: A068018 A294918 A331872 * A060798 A134320 A329227

Adjacent sequences:  A307064 A307065 A307066 * A307068 A307069 A307070

KEYWORD

nonn

AUTHOR

Ilya Gutkovskiy, Mar 22 2019

STATUS

approved

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Last modified April 12 00:16 EDT 2021. Contains 342910 sequences. (Running on oeis4.)