A294071 Number of ordered ways of writing n^2 as a sum of n squares > 1.

1, 0, 0, 0, 1, 5, 6, 7, 288, 262, 13702, 69531, 610567, 5356091, 51724960, 521956086, 5467658641, 59931636545, 690518644584, 8100858045744, 99142980567486, 1246972499954475, 16142015005905558, 215722810653380845, 2955759897694815985, 41614888439136252691

Offset

0,6

Links

Table of n, a(n) for n=0..25.

Index entries for sequences related to sums of squares

Formula

a(n) = [x^(n^2)] (Sum_{k>=2} x^(k^2))^n.

Example

a(5) = 5 because we have [9, 4, 4, 4, 4], [4, 9, 4, 4, 4], [4, 4, 9, 4, 4], [4, 4, 4, 9, 4] and [4, 4, 4, 4, 9].

Mathematica

Table[SeriesCoefficient[((-1 - 2 x + EllipticTheta[3, 0, x])/2)^n, {x, 0, n^2}], {n, 0, 25}]

Crossrefs

Cf. A000290, A037444, A066535, A078134, A092362, A232173, A280129, A280542, A281154, A281155, A298329, A298330, A298640, A298642.

Sequence in context: A048042 A048090 A048027 * A240661 A153430 A329089

Adjacent sequences: A294068 A294069 A294070 * A294072 A294073 A294074

Keyword

nonn

Author

Ilya Gutkovskiy, Feb 07 2018

Status

approved