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A151666
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Number of partitions of n into distinct powers of 4.
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20
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1, 1, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
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OFFSET
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0,1
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LINKS
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FORMULA
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G.f.: Prod_{k >= 0 } (1+x^(4^k)). Exponents give A000695.
G.f. A(x) satisfies: A(x) = (1 + x) * A(x^4). - Ilya Gutkovskiy, Aug 12 2019
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MATHEMATICA
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terms = 105;
kmax = Log[4, terms] // Ceiling;
CoefficientList[Product[1+x^(4^k), {k, 0, kmax}] + O[x]^(kmax terms), x][[1 ;; terms]] (* Jean-François Alcover, Jul 31 2018 *)
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PROG
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(Haskell)
a151666 n = fromEnum (n < 2 || m < 2 && a151666 n' == 1)
where (n', m) = divMod n 4
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CROSSREFS
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For generating functions Prod_{k>=0} (1+a*x^(b^k)) for the following values of (a,b) see: (1,2) A000012 and A000027, (1,3) A039966 and A005836, (1,4) A151666 and A000695, (1,5) A151667 and A033042, (2,2) A001316, (2,3) A151668, (2,4) A151669, (2,5) A151670, (3,2) A048883, (3,3) A117940, (3,4) A151665, (3,5) A151671, (4,2) A102376, (4,3) A151672, (4,4) A151673, (4,5) A151674.
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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