The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A076901 E.g.f.: 1/Product_{m>0} (1+(-x)^m/m!). 5
 1, 1, 1, 4, 21, 96, 520, 3795, 32053, 284368, 2763876, 30648465, 373339824, 4833294389, 67167087793, 1009753574739, 16215467043493, 275361718915824, 4947532173402532, 94054153646919213, 1882793796608183356, 39528099512321898363, 869222284280777733043 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,4 LINKS Seiichi Manyama, Table of n, a(n) for n = 0..200 FORMULA a(n) ~ c * n!, where c = Product_{k>=2} (1 + (-1)^k/k!) = 0.773515873861910082... - Vaclav Kotesovec, Sep 14 2017 MAPLE A076901 := proc(n) local a, s; s := proc(n) local d; add((-1)^d*n!/(d*(n/d)!^d), d = numtheory[divisors](n)) end: a := proc(n) option remember; local k; `if`(n=0, 1, add(binomial(n-1, k-1)*s(k)*a(n-k), k = 1..n)) end: (-1)^n*a(n) end: seq(A076901(n), n=0..20); # Peter Luschny, Apr 16 2011 MATHEMATICA nmax = 25; Table[SeriesCoefficient[Product[1/(1 + (-x)^k/k!), {k, 1, n}], {x, 0, n}], {n, 0, nmax}] * Range[0, nmax]! (* Vaclav Kotesovec, Sep 14 2017 *) CROSSREFS Cf. A005651, A182928. Sequence in context: A231377 A017967 A292308 * A080043 A240456 A113022 Adjacent sequences: A076898 A076899 A076900 * A076902 A076903 A076904 KEYWORD nonn AUTHOR Vladeta Jovovic, Nov 26 2002 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified September 16 22:04 EDT 2024. Contains 375979 sequences. (Running on oeis4.)