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Search: id:A113263
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| A113263 |
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a(n) is the number of ways the set {1^3, 2^3, ..., n^3} can be partitioned into two sets of equal sums. |
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+0
3
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| 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 2, 1, 0, 0, 2, 62, 0, 0, 268, 356, 0, 0, 2287, 1130, 0, 0, 5317, 36879, 0, 0, 203016, 319415, 0, 0, 2124580, 1631750, 0, 0, 10953868, 41280525, 0, 0, 242899218, 472958485, 0, 0, 2984270739, 3419746788, 0, 0, 24035122402
(list; graph; listen)
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OFFSET
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1,15
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COMMENT
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a(n)=0 when n == 1 or 2 mod 4.
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FORMULA
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a(n) is half the coefficient of x^0 in product(x^(k^3)+x^(k^-3), k=1..n).
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MAPLE
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A113263:=proc(n) local i, p, t; t:= NULL; p:=1; for i to n do p:=p*(x^(i^3)+x^(-i^3)); t:=t, coeff(p, x, 0)/2; od; t; end;
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MATHEMATICA
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p = 1; t = {}; Do[p = Expand[p(x^(n^3) + x^(-n^3))]; AppendTo[t, Select[ p, NumberQ[ # ] &]/2], {n, 56}]; t (* Robert G. Wilson v *)
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CROSSREFS
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Cf. A083527.
Sequence in context: A063181 A059220 A059431 this_sequence A063658 A132013 A128229
Adjacent sequences: A113260 A113261 A113262 this_sequence A113264 A113265 A113266
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KEYWORD
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nonn
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AUTHOR
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Floor van Lamoen (fvlamoen(AT)hotmail.com), Oct 21 2005
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EXTENSIONS
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More terms from Robert G. Wilson v (rgwv(at)rgwv.com) and T.D. Noe (noe(AT)sspectra.com), Oct 27 2005
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