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!)
A293850 Number of set partitions of [n^2] that are invariant under a permutation consisting of n n-cycles. 2
1, 1, 7, 42, 931, 6078, 560124, 3451290, 504673027, 10212362573, 1083069266634, 17595339114554, 13211434169884204, 109469680507411214, 36642712015230282784, 3131089417758323092388, 735014776353108421594259, 19549131844625243949179686 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,3
LINKS
FORMULA
a(n) = A162663(n,n).
MAPLE
b:= proc(n, k) option remember; `if`(n=0, 1, add(binomial(n-1, j-1)
*add(d^(j-1), d=numtheory[divisors](k))*b(n-j, k), j=1..n))
end:
a:= n-> b(n$2):
seq(a(n), n=0..18);
MATHEMATICA
b[n_, k_] := b[n, k] = If[n == 0, 1, Sum[Binomial[n - 1, j - 1] Sum[d^(j - 1), {d, Divisors[k]}] b[n - j, k], {j, 1, n}]];
a[n_] := b[n, n];
a /@ Range[0, 18] (* Jean-François Alcover, Dec 12 2020, after Alois P. Heinz *)
CROSSREFS
Cf. A162663.
Sequence in context: A133669 A205340 A304953 * A202862 A229437 A043064
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Oct 17 2017
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 March 28 14:38 EDT 2024. Contains 371254 sequences. (Running on oeis4.)