A276637 Number of up-down sequences with n copies each of 1,2,...,5.

1, 16, 936, 87336, 9929000, 1267945800, 174470351760, 25288627665840, 3812023555600680, 591698219294831040, 94094630284245419136, 15245574601442117896656, 2511237778001138580615056, 419023242828557373939828896, 70761397145460782667032755200

Offset: 0

Author

Alois P. Heinz, Sep 08 2016

Keywords

• nonn

Examples

			a(1) = 16: 13254, 14253, 14352, 15243, 15342, 23154, 24153, 24351, 25143, 25341, 34152, 34251, 35142, 35241, 45132, 45231.
a(2) = 936: 1213243545, 1213254534, 1214243535, 1214253435, ..., 4545121323, 4545132312, 4545231213, 4545231312.
		

Crossrefs

Row n=5 of A275784.