A273184 The H_4-Eulerian numbers.

1, 2636, 9126, 2636, 1

Offset: 0

Author

Tom Edgar, May 17 2016

Keywords

• nonn
• fini
• full

Comments

a(n) is the number of elements of the Weyl group H_4 that have a descent set of size n.

Sum_{n=0..4} a(n) = 14400, which is the order of the group H_4.

References

• T. K. Petersen, Eulerian Numbers, Birkhauser, 2015, Table 11.5.

Crossrefs

Cf. A008292, A060187, A066094, A273000, A273035, A273036, A273181, A273183.