|
|
A228509
|
|
a(n) = binomial(n^2+n+1,n) * (n+1) / (n^2+n+1) for n>=0.
|
|
0
|
|
|
1, 2, 9, 88, 1425, 32886, 992446, 37106784, 1657248417, 86128357150, 5107663394691, 340427678198400, 25194445531808735, 2050156960934135340, 181938723871328671500, 17487609556155439051136, 1809886850192627028383553, 200670984392566362698014110, 23730570474434159458296269953
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,2
|
|
LINKS
|
|
|
FORMULA
|
|
|
EXAMPLE
|
G.f.: A(x) = 1 + 2*x + 9*x^2 + 88*x^3 + 1425*x^4 + 32886*x^5 +...
|
|
MATHEMATICA
|
Table[(Binomial[n^2+n+1, n](n+1))/(n^2+n+1), {n, 0, 20}] (* Harvey P. Dale, Oct 13 2015 *)
|
|
PROG
|
(PARI) {a(n)=binomial(n^2+n+1, n)*(n+1)/(n^2+n+1)}
for(n=0, 20, print1(a(n), ", "))
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|