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A309025 Expansion of x * Product_{k>=0} (1 + x^(2^k) + x^(2^(k+3))). 1
0, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 2, 1, 2, 1, 2, 1, 3, 2, 2, 1, 3, 2, 2, 1, 4, 2, 2, 1, 4, 2, 2, 1, 5, 3, 3, 2, 4, 2, 2, 1, 6, 3, 4, 2, 4, 2, 2, 1, 7, 4, 4, 2, 4, 2, 2, 1, 8, 4, 4, 2, 4, 2, 2, 1, 9, 5, 5, 3, 5, 3, 3, 2, 9, 4, 5, 2, 5, 2, 3, 1, 10, 6, 5, 3, 6, 4, 3, 2, 10, 4, 5, 2, 6, 2, 3, 1, 11, 7, 6, 4 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,10

LINKS

Table of n, a(n) for n=0..100.

FORMULA

a(n) = 0 for n <= 0, a(1) = 1; a(2*n) = a(n), a(2*n+1) = a(n-3) + a(n+1).

MATHEMATICA

nmax = 100; CoefficientList[Series[x Product[(1 + x^(2^k) + x^(2^(k + 3))), {k, 0, Floor[Log[2, nmax]] + 1}], {x, 0, nmax}], x]

CROSSREFS

Cf. A002487, A112970, A309026.

Sequence in context: A338651 A033107 A239061 * A247599 A083897 A025823

Adjacent sequences:  A309022 A309023 A309024 * A309026 A309027 A309028

KEYWORD

nonn

AUTHOR

Ilya Gutkovskiy, Jul 07 2019

STATUS

approved

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Last modified January 23 17:33 EST 2022. Contains 350514 sequences. (Running on oeis4.)