|
|
A367876
|
|
Expansion of e.g.f. exp(x * (2 - exp(x))).
|
|
1
|
|
|
1, 1, -1, -8, -15, 46, 445, 1240, -4319, -63782, -282219, 474508, 16681489, 119013142, 137086573, -6217558664, -73971468351, -333213031502, 2327570156197, 58209718600324, 509023624616881, 613709076338926, -48850389688059651, -773649504707845328
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,4
|
|
LINKS
|
|
|
FORMULA
|
G.f.: Sum_{k>=0} (-x)^k / (1 - (k+2)*x)^(k+1).
a(n) = Sum_{k=0..n} (-1)^k * (k+2)^(n-k) * binomial(n,k).
|
|
PROG
|
(PARI) a(n) = sum(k=0, n, (-1)^k*(k+2)^(n-k)*binomial(n, k));
|
|
CROSSREFS
|
|
|
KEYWORD
|
sign,easy
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|