|
|
A081917
|
|
a(0)=1, a(n)= n^(n-2)(7n^2-3n+2)/6 (n>0).
|
|
1
|
|
|
1, 1, 4, 28, 272, 3375, 50976, 907578, 18612224, 432061533, 11200000000, 320680885976, 10051252125696, 342302635261067, 12586048547315712, 496928474121093750, 20968759865037029376, 941737183946729395897
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,3
|
|
COMMENTS
|
Main diagonal of square array defined by T(n,k)=k^n(n^3-3n^2+2n+6k^3)/(6k^3), in which rows have g.f. (1-3kx+3k^2x^2-(k^3-1)x^3)/(1-kx)^4.
|
|
LINKS
|
|
|
CROSSREFS
|
|
|
KEYWORD
|
easy,nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|