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”).

A319336
Denominator of the average of the averages of all integer partitions of n.
2
1, 2, 6, 15, 84, 55, 100, 770, 1680, 1323, 141120, 8470, 27720, 3474900, 4228224, 3468465, 19459440, 131030900, 109156320, 1042578108, 8779605120, 1514663280, 41736380400, 175685635125, 24960905112, 1254125149200, 4476730258000, 10664476594200, 73326164511600
OFFSET
1,2
LINKS
EXAMPLE
The sequence of average averages begins: 1, 3/2, 11/6, 31/15, 187/84, 131/55, 247/100, 1993/770, 4463/1680, 3635/1323.
MATHEMATICA
Table[Denominator[Mean[Mean/@IntegerPartitions[n]]], {n, 20}]
PROG
(PARI) seq(n)={[denominator(poldegree(p)*subst(intformal(p/y)/p, y, 1)) | p <- Vec(-1+1/prod(k=1, n, 1 - x^k*y + O(x*x^n)))]} \\ Andrew Howroyd, Sep 19 2018
CROSSREFS
Numerators are in A319335.
Sequence in context: A244443 A346555 A356223 * A007709 A190339 A078328
KEYWORD
nonn,frac
AUTHOR
Gus Wiseman, Sep 17 2018
STATUS
approved