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A298936 Number of ordered ways of writing n^2 as a sum of n nonnegative cubes. 2
1, 1, 0, 6, 6, 20, 120, 7, 1689, 6636, 36540, 64020, 963996, 2894892, 19555965, 176079995, 955611188, 6684303780, 42462792168, 292378003753, 1886275214112, 13384059605364, 87399249887334, 624073002367892, 5080120229014734, 37587589611771480 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

LINKS

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

Index entries for sequences related to sums of cubes

FORMULA

a(n) = [x^(n^2)] (Sum_{k>=0} x^(k^3))^n.

EXAMPLE

a(3) = 6 because we have [8, 1, 0], [8, 0, 1], [1, 8, 0], [1, 0, 8], [0, 8, 1] and [0, 1, 8].

MAPLE

f:= n -> coeff(add(x^(k^3), k=0..floor(n^(2/3)))^n, x, n^2):

map(f, [$0..30]); # Robert Israel, Jan 29 2018

MATHEMATICA

Table[SeriesCoefficient[Sum[x^k^3, {k, 0, Floor[n^(2/3) + 1]}]^n, {x, 0, n^2}], {n, 0, 25}]

CROSSREFS

Cf. A000290, A000578, A023358, A030272, A218495, A259792, A291700, A298671, A298672, A298934, A298937.

Sequence in context: A309122 A115046 A004983 * A034695 A198340 A189980

Adjacent sequences:  A298933 A298934 A298935 * A298937 A298938 A298939

KEYWORD

nonn

AUTHOR

Ilya Gutkovskiy, Jan 29 2018

STATUS

approved

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Last modified February 23 14:41 EST 2020. Contains 332163 sequences. (Running on oeis4.)