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

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A354849 a(n) = (n-1)! * Sum_{d|n} d^(n/d) / (d-1)!. 2
1, 3, 5, 34, 29, 1626, 727, 99128, 584649, 12353050, 3628811, 4648976652, 479001613, 803709466574, 11133394272015, 391883024332816, 20922789888017, 312756670075449618, 6402373705728019, 148614866400768768020, 2663970255433783296021 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
LINKS
FORMULA
E.g.f.: -Sum_{k>0} log(1 - k * x^k)/k!.
If p is prime, a(p) = p + (p-1)!.
MATHEMATICA
a[n_] := (n - 1)! * DivisorSum[n, #^(n/#)/(# - 1)! &]; Array[a, 20] (* Amiram Eldar, Jun 08 2022 *)
PROG
(PARI) a(n) = (n-1)!*sumdiv(n, d, d^(n/d)/(d-1)!);
(PARI) my(N=30, x='x+O('x^N)); Vec(serlaplace(-sum(k=1, N, log(1-k*x^k)/k!)))
CROSSREFS
Cf. A087906.
Sequence in context: A332704 A263295 A222484 * A222630 A187993 A221158
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Jun 08 2022
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.

License Agreements, Terms of Use, Privacy Policy. .

Last modified July 19 14:58 EDT 2024. Contains 374410 sequences. (Running on oeis4.)