A324961 a(n) is the coefficient of y^n in Product_{k=0..n-1} (1 + (k+2)*y + y^2), for n >= 0.

1, 2, 8, 42, 268, 2000, 17038, 162890, 1725372, 20044728, 253332924, 3459443988, 50751642214, 795946804016, 13287749613058, 235247030990910, 4402121435984292, 86812342423952520, 1799413314325764232, 39108496756464803888, 889322428578635843156, 21117181548344260655472, 522654439233442389220252, 13460850532654848043445348, 360199399036948435113653582, 10000217284416098095635943300, 287673368509370723571678876660, 8564090161107702738179495471400

Offset: 0

Author

Paul D. Hanna, Mar 20 2019

Keywords

• nonn

Comments

a(n) = A324960(n,n) for n >= 0.

Crossrefs

Cf. A324960, A324962.

Programs

PARI

{a(n) = polcoeff( prod(m=0, n-1, 1 + (m+2)*y + y^2 +y*O(y^n)), n, y)}
for(n=0, 30, print1(a(n), ", "))