|
|
A205803
|
|
E.g.f.: -log( Sum_{n>=0} (-x)^(n*(n+1)/2) / (n*(n+1)/2)! ).
|
|
3
|
|
|
1, 1, 3, 10, 44, 249, 1693, 13384, 120932, 1229759, 13894429, 172677450, 2341111850, 34385290940, 543885462121, 9217332132024, 166621796893824, 3200275345024464, 65082833538054240, 1397097303096855578, 31569176387677926733, 749012642530028865010
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,3
|
|
LINKS
|
|
|
EXAMPLE
|
E.g.f.: A(x) = x + x^2/2! + 3*x^3/3! + 10*x^4/4! + 44*x^5/5! + 249*x^6/6! +...
where
exp(-A(x)) = 1 - x - x^3/3! + x^6/6! + x^10/10! - x^15/15! - x^21/21! +...
|
|
PROG
|
(PARI) {a(n) = n!*polcoeff(-log(sum(m=0, sqrtint(2*n+1), (-x)^(m*(m+1)/2)/(m*(m+1)/2)!+x*O(x^n))), n)}
for(n=1, 25, print1(a(n), ", "))
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|