A350283 a(n) is the constant term in the expansion of Product_{k=1..n} (x^k + 1/x^k)^k.

1, 0, 0, 6, 76, 0, 0, 7559080, 1509040932, 0, 0, 887531129680197018, 3078434842626707386602, 0, 0, 8813577747274880345454470354985336, 509819403352972623999938010230619997952, 0, 0, 6578453931935965721022496238115694708685746283712759572

Offset

0,4

Links

Seiichi Manyama, Table of n, a(n) for n = 0..50

Formula

a(4*n+1) = a(4*n+2) = 0.

Prog

(PARI) a(n) = polcoef(prod(k=1, n, (x^k+1/x^k)^k), 0);

Crossrefs

Cf. A350282.

Sequence in context: A185289 A336228 A326011 * A350411 A263228 A229571

Adjacent sequences: A350280 A350281 A350282 * A350284 A350285 A350286

Keyword

nonn

Author

Seiichi Manyama, Dec 23 2021

Status

approved