A292522 Number of solutions to +- 1^3 +- 3^3 +- 5^3 +- 7^3 +- ... +- (4*n-1)^3 = 0.

1, 0, 0, 0, 0, 0, 0, 0, 2, 6, 2, 10, 118, 88, 254, 3308, 2558, 9578, 84568, 121804, 496396, 3312400, 5755724, 19021024, 116780256, 241754350, 883730786, 4923089216, 11668601596, 42357336066, 205859270250, 538878582526, 1974181071852, 9194146886086, 26277093562150

Offset

0,9

Links

Table of n, a(n) for n=0..34.

Formula

Constant term in the expansion of Product_{k=1..2*n} (x^((2*k-1)^3)+1/x^((2*k-1)^3)).

Example

For n=8 the 2 solutions are
+1^3-3^3-5^3+7^3-9^3+11^3+13^3-15^3-17^3+19^3+21^3-23^3+25^3-27^3-29^3+31^3 = 0 and
-1^3+3^3+5^3-7^3+9^3-11^3-13^3+15^3+17^3-19^3-21^3+23^3-25^3+27^3+29^3-31^3 = 0.

Crossrefs

Cf. A158118, A292476, A292496.

Sequence in context: A136761 A136698 A223473 * A243197 A319048 A066900

Adjacent sequences: A292519 A292520 A292521 * A292523 A292524 A292525

Keyword

nonn

Author

Seiichi Manyama, Sep 18 2017

Extensions

a(29)-a(34) from Alois P. Heinz, Sep 18 2017

Status

approved