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

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A308345 Expansion of e.g.f. Sum_{k>=1} log(1/(1 - x^k/k)). 5
 1, 2, 4, 15, 48, 310, 1440, 11970, 85120, 821016, 7257600, 91707000, 958003200, 13440913200, 178919989248, 2809456650000, 41845579776000, 763629026160000, 12804747411456000, 257140635922025856, 4918792391884800000, 106876408948152480000 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Seiichi Manyama, Table of n, a(n) for n = 1..450 FORMULA a(n) = n! * Sum_{d|n} 1/(d*(n/d)^d). a(n) = A007841(n) - (1/n) * Sum_{k=1..n-1} k*binomial(n,k)*A007841(n-k)*a(k). a(n) ~ 2 * (n-1)!. - Vaclav Kotesovec, Feb 16 2020 MATHEMATICA nmax = 22; CoefficientList[Series[Sum[Log[1/(1 - x^k/k)], {k, 1, nmax}], {x, 0, nmax}], x] Range[0, nmax]! // Rest Table[n! Sum[1/(d (n/d)^d), {d, Divisors[n]}], {n, 1, 22}] CROSSREFS Cf. A007841, A038048, A182926, A182927, A308337. Sequence in context: A277508 A332234 A316726 * A280065 A188228 A243796 Adjacent sequences: A308342 A308343 A308344 * A308346 A308347 A308348 KEYWORD nonn AUTHOR Ilya Gutkovskiy, May 21 2019 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 June 3 11:24 EDT 2023. Contains 363110 sequences. (Running on oeis4.)