A131611 E.g.f.: (x^2/2-2*x+3)*tan(x/2+Pi/4)-3*x^3-x-3.

0, 0, 0, -15, 5, 18, 66, 298, 1511, 8670, 55168, 386394, 2951673, 24428654, 217723390, 2079109386, 21177620171, 229195610430, 2626388037372, 31768201320634, 404485298533085, 5407570127090958, 75736453324821754, 1108952444876609898, 16943545270848408495

Offset

0,4

Links

Table of n, a(n) for n=0..24.

Y. Sano, The principal numbers of K. Saito for the types A_l, D_l and E_l, Discr. Math., 307 (2007), 2636-2642.

Formula

a(n) ~ n! * 2^(n-1) * (24 + (Pi-8)*Pi) / Pi^(n+1). - Vaclav Kotesovec, Mar 12 2019

Crossrefs

Cf. A131656.

Sequence in context: A004480 A114332 A051998 * A166209 A040215 A335879

Adjacent sequences: A131608 A131609 A131610 * A131612 A131613 A131614

Keyword

sign

Author

N. J. A. Sloane, Oct 30 2007

Status

approved