A090646 a(n) = (-1)^(n+1)*6*(36^n-1)*B(2n) where B(k) denotes the k-th Bernoulli number.

0, 35, 259, 6665, 335923, 27484625, 3305838667, 548549148665, 120046523944291, 33497222700551585, 11607372388687929595, 4890106826755096362185, 2461501533722532841839379, 1459003091037934911760465265, 1005821157267400660295054486443, 797963050933435369745105061961625

Offset

0,2

Links

Table of n, a(n) for n=0..15.

Mathematica

a[n_] := (-1)^(n+1) * 6 * (36^n-1)*BernoulliB[2*n]; Array[a, 14, 0] (* Amiram Eldar, May 03 2025 *)

Prog

(PARI) a(n)=(-1)^(n+1)*6*(36^n-1)*bernfrac(2*n);

Crossrefs

Cf. A027641, A027642.

Sequence in context: A372927 A267022 A145014 * A220929 A251931 A267627

Adjacent sequences: A090643 A090644 A090645 * A090647 A090648 A090649

Keyword

nonn

Author

Benoit Cloitre, Dec 13 2003

Status

approved