A283612 Number of sets of sequences of total length n over an alphabet of n letters with the symmetric group acting on the letters.

1, 1, 4, 13, 57, 252, 1322, 7361, 45057, 294392, 2054394, 15172872, 118175823, 966300054, 8268640847, 73825951226, 686049132714, 6620780612228, 66224775509130, 685372810735380, 7327272883303533

Offset

0,3

References

E. Palmer and F. Harary, Graphical Enumeration, Academic Press, 1973.

Links

Table of n, a(n) for n=0..20.

Bob Lucassen, Marko Riedel, Counting sets of unlabeled sequences of total cardinality n

Marko Riedel, Maple code for A283612 by total enumeration and by Power Group Enumeration.

Crossrefs

Sequence in context: A149479 A149480 A151481 * A039626 A149481 A149482

Adjacent sequences: A283609 A283610 A283611 * A283613 A283614 A283615

Keyword

nonn,more

Author

Marko Riedel, Mar 11 2017

Status

approved