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A121663
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a(0) = 1; if n = 2^k, a(n) = k+2, otherwise a(n)=(A000523(n)+2)*a(A053645(n)).
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6
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1, 2, 3, 6, 4, 8, 12, 24, 5, 10, 15, 30, 20, 40, 60, 120, 6, 12, 18, 36, 24, 48, 72, 144, 30, 60, 90, 180, 120, 240, 360, 720, 7, 14, 21, 42, 28, 56, 84, 168, 35, 70, 105, 210, 140, 280, 420, 840, 42, 84, 126, 252, 168, 336, 504, 1008, 210, 420, 630, 1260, 840, 1680
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OFFSET
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0,2
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COMMENTS
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Each n occurs A045778(n) times in the sequence.
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LINKS
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FORMULA
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G.f.: Product_{k>=0} (1 + (k + 2) * x^(2^k)). - Ilya Gutkovskiy, Aug 19 2019
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MATHEMATICA
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f[0] := 1; f[n_] := If[(b = n - 2^(k = Floor[Log2[n]])) == 0, k + 2, (k + 2)*f[b]]; Table[f[n], {n, 0, 61}] (* Ivan Neretin, May 09 2015 *)
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PROG
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(define (pow2? n) (and (> n 0) (zero? (A004198bi n (- n 1)))))
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CROSSREFS
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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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