[go: up one dir, main page]

login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A229263
E.g.f.: Product_{n>=1} cosh(x^n).
9
1, 1, 13, 541, 32761, 3782521, 570649861, 126354119893, 34059666142321, 12697511966492401, 5418397453551516541, 2950382131846118771341, 1848796902719228099999593, 1394126061848631877574788201, 1187817128863650862040235107701, 1196980698779612997551160117313861
OFFSET
0,3
LINKS
EXAMPLE
E.g.f.: A(x) = 1 + x^2/2! + 13*x^4/4! + 541*x^6/6! + 32761*x^8/8! +...
where
A(x) = cosh(x)*cosh(x^2)*cosh(x^3)*cosh(x^4)*cosh(x^5)*cosh(x^6)*...
PROG
(PARI) {a(n)=(2*n)!*polcoeff(prod(m=1, n, cosh(x^m +x*O(x^(2*n)))), 2*n)}
for(n=0, 20, print1(a(n), ", "))
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Sep 18 2013
STATUS
approved