|
|
A132962
|
|
a(n) = n!*Sum_{d|n} (-1)^(d+1)/(d!*(n/d)!^d).
|
|
8
|
|
|
1, 0, 2, -3, 2, 5, 2, -140, 282, 819, 2, -20482, 2, 133419, 1527528, -4661085, 2, -153296429, 2, 1402482796, 36278688162, 13748957859, 2, -14081800718427, 5194672859378, 7905848380325, 2977584150505252, 12956452725792600, 2, -1314647260913859151
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,3
|
|
LINKS
|
|
|
FORMULA
|
E.g.f.: Sum_{k>0}(1-exp(-x^k/k!)).
|
|
MATHEMATICA
|
Rest[ Range[0, 30]! CoefficientList[ Series[ Sum[1 - Exp[ -x^k/k! ], {k, 30}], {x, 0, 30}], x]] (* Robert G. Wilson v, Sep 13 2007 *)
|
|
PROG
|
(PARI) a(n) = n!*sumdiv(n, d, (-1)^(d+1)/(d!*(n/d)!^d)); \\ Michel Marcus, Sep 29 2017
|
|
CROSSREFS
|
|
|
KEYWORD
|
easy,sign
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|