A115189 Third diagonal (M=3) of triangle A115154 (called Y(3,1)).

1, 40, 466, 4870, 50053, 516256, 5371210, 56422444, 598180570, 6395471992, 68897550064, 747270112390, 8154207352045, 89462667739360, 986322436120690, 10922076949690180, 121428345789834430, 1354895520307913680

Offset

0,2

Links

Table of n, a(n) for n=0..17.

Formula

a(n)= A115154(n+2,n+1), n>=0.

Recurrence: a(n)= b(n) - 6*b(n-1), with b(n):=A064063(n+3), n>=0.

G.f.: ((-3+9*x +2*x^2) + 3*(1-6*x)*c(3*x))/((2+x)*x^2), with the o.g.f. c(x) of A000108 (Catalan).

Example

466 = a(2) = A064063(5) - 6*A064063(4) = 1606 - 6*190.

Crossrefs

Sequence in context: A210348 A055750 A290611 * A186933 A271650 A177096

Adjacent sequences: A115186 A115187 A115188 * A115190 A115191 A115192

Keyword

nonn,easy

Author

Wolfdieter Lang, Feb 23 2006

Status

approved