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A113263 a(n) is the number of ways the set {1^3, 2^3, ..., n^3} can be partitioned into two sets of equal sums. 4
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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,15

COMMENTS

a(n)=0 when n == 1 or 2 mod 4.

LINKS

Alois P. Heinz and Ray Chandler, Table of n, a(n) for n = 1..130 (first 100 terms from Alois P. Heinz)

FORMULA

a(n) is half the coefficient of x^0 in product(x^(k^3)+x^(k^-3), k=1..n).

MAPLE

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;

MATHEMATICA

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 *)

CROSSREFS

Cf. A058498, A083527.

Sequence in context: A261630 A059431 A271698 * A063658 A237053 A209777

Adjacent sequences:  A113260 A113261 A113262 * A113264 A113265 A113266

KEYWORD

nonn

AUTHOR

Floor van Lamoen, Oct 21 2005

EXTENSIONS

More terms from Robert G. Wilson v and Tony Noe, Oct 27 2005

STATUS

approved

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Last modified March 28 05:07 EDT 2017. Contains 284182 sequences.