A292497 - OEIS

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A292497

Number of solutions to 1^2 +- 3^2 +- 5^2 +- 7^2 +- ... +- (4*n-1)^2 = 0.

1, 0, 0, 0, 1, 0, 6, 0, 20, 5, 258, 62, 2510, 914, 24285, 16403, 263945, 222240, 3068971, 3241157, 35286928, 46638022, 426740187, 650095127, 5330192371, 9185814630, 67064945191, 129902075662, 864443143567, 1833530501143, 11336065334984, 25990268638322

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,7

LINKS

Seiichi Manyama, Table of n, a(n) for n = 0..100

FORMULA

For n>0 constant term in the expansion of 1/2 * Product_{k=1..2*n} (x^(2*k-1)^2+1/x^(2*k-1)^2).

a(n) = A292496(n)/2 for n>0.

CROSSREFS

Cf. A083527, A156700, A292496.

Sequence in context: A304878 A167356 A219540 * A082731 A272673 A167357

Adjacent sequences: A292494 A292495 A292496 * A292498 A292499 A292500

KEYWORD

nonn

AUTHOR

Seiichi Manyama, Sep 17 2017

STATUS

approved