|
|
A132304
|
|
Sum of fourth powers of trinomial coefficients: a(n) = Sum_{k=0..2n} trinomial(n,k)^4 where trinomial(n,k) = [x^k] (1 + x + x^2)^n.
|
|
2
|
|
|
1, 3, 115, 5157, 281907, 16688953, 1043460469, 67769148555, 4527813298227, 309207348577017, 21487099512128265, 1514508365575327455, 108015601963868232885, 7780760215720406500095, 565264860408377433558523
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,2
|
|
LINKS
|
|
|
PROG
|
(PARI) a(n)=sum(k=0, 2*n, polcoeff((1+x+x^2)^n, k)^4)
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|