A094311 n(1+n^2)((2+n^2)^2-n^2)/16.

1, 20, 210, 1309, 5720, 19536, 55825, 139490, 314019, 650440, 1258796, 2302455, 4015570, 6724004, 10870035, 17041156, 26003285, 38738700, 56489014, 80803505, 113593116, 157190440, 214416005, 288651174, 383917975, 504966176, 657367920

Offset

1,2

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Index entries for linear recurrences with constant coefficients, signature (8, -28, 56, -70, 56, -28, 8, -1).

Formula

a(1)=1, a(2)=20, a(3)=210, a(4)=1309, a(5)=5720, a(6)=19536, a(7)=55825, a(8)=139490, a(n)=8*a(n-1)-28*a(n-2)+56*a(n-3)-70*a(n-4)+56*a(n-5)-28*a(n-6)+8*a(n-7)-a (n-8) [From Harvey P. Dale, Oct 17 2011]

G.f.: (x*(x+1)*(x*(x*(x*(x+11)+67)+66)+12)+1)/(x-1)^8 [From Harvey P. Dale, Oct 17 2011]

Mathematica

Table[n(1+n^2)((2+n^2)^2-n^2)/16, {n, 30}] (* or *) LinearRecurrence[ {8, -28, 56, -70, 56, -28, 8, -1}, {1, 20, 210, 1309, 5720, 19536, 55825, 139490}, 30] (* Harvey P. Dale, Oct 17 2011 *)

Crossrefs

Sequence in context: A161880 A074668 A139620 * A353895 A353884 A162640

Adjacent sequences: A094308 A094309 A094310 * A094312 A094313 A094314

Keyword

nonn

Author

Amarnath Murthy, Apr 29 2004

Extensions

Edited by N. J. A. Sloane following a suggestion from Zak Seidov, Mar 28 2008

Status

approved