|
|
A308389
|
|
a(n) = (1/n!) * Sum_{i_1=1..4} Sum_{i_2=1..4} ... Sum_{i_n=1..4} (-1)^(i_1 + i_2 + ... + i_n) * multinomial(i_1 + i_2 + ... + i_n; i_1, i_2, ..., i_n).
|
|
1
|
|
|
1, 0, 15, 2380, 1056496, 1006985994, 1762986495425, 5113595093793395, 22839265373518360690, 148735602883834110187329, 1353820891564948063221216616, 16652183007514287292261315076600, 269267286009015985660399792630965620, 5594310615550213586375706097295466365365
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,3
|
|
LINKS
|
|
|
PROG
|
(PARI) {a(n) = sum(i=n, 4*n, (-1)^i*i!*polcoef(sum(j=1, 4, x^j/j!)^n, i))/n!}
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|