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A184714
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Number of words of numbers x(1), ..., x(n), in 0..3 such that Sum_{i=1..n} i*x(i)^3 = 27*n.
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1
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1, 1, 2, 2, 7, 19, 39, 120, 411, 1310, 3862, 11059, 31849, 89615, 247305, 674579, 1812940, 4806211, 12576930, 32509641, 83052304, 209808493, 524424707, 1297623584, 3179903180, 7721053410, 18582920108, 44349211490, 104989527861
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OFFSET
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1,3
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COMMENTS
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Column 3 of A184720.
Coefficient of x^(27*n) in Product_{i=1..n} (1 + x^i + x^(8*i) + x^(27*i)). - Robert Israel, Jul 03 2018
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LINKS
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R. H. Hardin, Table of n, a(n) for n = 1..102
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EXAMPLE
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All solutions for n=5:
0 0 3 2 1 1 2
0 3 0 2 1 2 1
0 3 0 1 2 3 3
0 0 3 3 3 2 1
3 0 0 0 0 1 2
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MAPLE
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F:= proc(n, s) option remember; if n = 1 or s < 0 then 0 else add(procname(n-1, s-n*j^3), j=0..3) fi end proc:
F(1, 0):= 1: F(1, 1):= 1: F(1, 8):= 1: F(1, 27):= 1:
seq(F(n, n*27), n=1..50); # Robert Israel, Jul 03 2018
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CROSSREFS
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Sequence in context: A338415 A243022 A049955 * A156464 A156520 A307426
Adjacent sequences: A184711 A184712 A184713 * A184715 A184716 A184717
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KEYWORD
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nonn
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AUTHOR
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R. H. Hardin, Jan 20 2011
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STATUS
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approved
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