A108915 Dimensions of the invariant subspaces in a sequence of modules of dimension (n+1)^(n-1) over the symmetric groups S_n.

1, 2, 3, 6, 12, 27, 61, 142, 338, 821, 2010, 4967, 12395, 31165, 78821, 200476, 512546, 1316337, 3394202, 8784064, 22809135, 59407930, 155162456, 406294516, 1066407001, 2805143797, 7393812949, 19525497125, 51653666339, 136872356055

Offset

1,2

Links

Table of n, a(n) for n=1..30.

Formula

No simple formula is known, only a complicated sum over partitions.

Example

a(3)=3 in the module M_3 = 3 s_{3} + 6 s_{2,1} + s_{1,1,1}.

Crossrefs

Cf. A000272.

Sequence in context: A024422 A186771 A019525 * A082395 A061343 A057649

Adjacent sequences: A108912 A108913 A108914 * A108916 A108917 A108918

Keyword

nonn

Author

F. Chapoton, Jul 18 2005

Status

approved