OFFSET
0,1
LINKS
T. D. Noe, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (11,-55,165,-330,462,-462,330,-165,55,-11,1).
FORMULA
G.f.: -28*(x+2)*(2*x+1) / (x-1)^11. - Colin Barker, Jan 28 2013
From Amiram Eldar, Sep 01 2022: (Start)
Sum_{n>=0} 1/a(n) = 580367/1764 - 100*Pi^2/3.
Sum_{n>=0} (-1)^n/a(n) = 74537/588 - 1280*log(2)/7. (End)
EXAMPLE
a(0) = C(0+5,0)*C(0+8,5) = C(5,0)*C(8,5) = 1*56 = 56
a(6) = C(6+5,6)*C(6+8,5) = C(11,6)*C(14,5) = 462*2002 = 924924.
MAPLE
with(combinat); for i from 0 to 25 do print(i, numbcomb(i+5, i)*numbcomb(i+8, 5)); end; # Jim Nastos, Oct 26 2005
MATHEMATICA
a[n_] := Binomial[n + 5, 5] * Binomial[n + 8, 5]; Array[a, 25, 0] (* Amiram Eldar, Sep 01 2022 *)
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Zerinvary Lajos, Apr 27 2005
EXTENSIONS
More terms from Jim Nastos, Oct 26 2005
STATUS
approved