A344400 a(n) = [x^n] 6*(8*x^3 + 3*x + 1) / (1 - 4*x)^(7/2).

6, 102, 1008, 7860, 53340, 330372, 1918224, 10615176, 56602260, 293032740, 1481004096, 7337198232, 35743534008, 171641101800, 814046047200, 3819148459920, 17747499595140, 81776562767460, 373968175442400, 1698587342436600, 7667851012141320, 34422129328312440

Offset

0,1

Comments

The sequence and its sister sequence A344401 are related to Frédéric Chapoton's sequences A344228 and A344321, as described in the linked remark.

Links

Table of n, a(n) for n=0..21.

Peter Luschny, Remark regarding A344228 and A344321.

Formula

a(n) = A344228(n+1)*(n+1)*(n+2). - John Keith, May 23 2021

Maple

aList := proc(len) local gf, ser;
   gf := 6*(8*x^3 + 3*x + 1) / (1 - 4*x)^(7/2):
   ser := series(gf, x, len+2): seq(coeff(ser, x, n), n = 0..len) end:
aList(21);

Crossrefs

Cf. A344401, A344228, A344321.

Sequence in context: A218462 A065990 A306406 * A277662 A371250 A022025

Adjacent sequences: A344397 A344398 A344399 * A344401 A344402 A344403

Keyword

nonn

Author

Peter Luschny, May 16 2021

Status

approved