A181888 Second column of triangle in A182971.

0, 0, 9, 64, 259, 784, 1974, 4368, 8778, 16368, 28743, 48048, 77077, 119392, 179452, 262752, 375972, 527136, 725781, 983136, 1312311, 1728496, 2249170, 2894320, 3686670, 4651920, 5818995, 7220304, 8892009, 10874304, 13211704, 15953344, 19153288, 22870848, 27170913, 32124288, 37808043, 44305872, 51708462, 60113872

Offset

1,3

Comments

These are scaled central factorial numbers (see A182971).

Links

Table of n, a(n) for n=1..40.

Index entries for linear recurrences with constant coefficients, signature (7, -21, 35, -35, 21, -7, 1).

Formula

G.f.: x^3*(9+x)/(1-x)^7.

a(1)=0, a(2)=0, a(3)=0, a(4)=9, a(5)=64, a(6)=259, a(7)=784, a(n) = 7*a(n-1) -21*a(n-2)+35*a(n-3)-35*a(n-4)+21*a(n-5)-7*a(n-6)+a(n-7). - Harvey P. Dale, Jul 03 2013

Mathematica

CoefficientList[Series[x^3(9+x)/(1-x)^7, {x, 0, 40}], x] (* or *) LinearRecurrence[ {7, -21, 35, -35, 21, -7, 1}, {0, 0, 0, 9, 64, 259, 784}, 50] (* Harvey P. Dale, Jul 03 2013 *)

Crossrefs

Cf. A182971. Bisections give A001823 and A181889.

Sequence in context: A016886 A099761 A018201 * A000444 A143631 A083328

Adjacent sequences: A181885 A181886 A181887 * A181889 A181890 A181891

Keyword

nonn

Author

N. J. A. Sloane, Feb 01 2011

Status

approved