A213862 Number of words w where each letter of the n-ary alphabet occurs n times and for every prefix z of w we have #(z,a_i) = 0 or #(z,a_i) >= #(z,a_j) for all j>i and #(z,a_i) counts the occurrences of the i-th letter in z.

1, 1, 3, 106, 115955, 7236515981, 40684710729862072, 29745278219128813035415595, 3847028733161627562733350467148495403, 114752550881830601773639529476205016572641397025904, 996942995951678818059423286104073541295789338859855813183302036541

Offset: 0

Author

Alois P. Heinz, Jun 23 2012

Keywords

• nonn

Examples

			a(0) = 1: the empty word.
a(1) = 1: a.
a(2) = 3: aabb, abab, baab.
a(3) = 106: aaabbbccc, aaabbcbcc, aaabbccbc, ..., cbaababcc, cbaabacbc, cbaabcabc.
		

Crossrefs

Main diagonal of A213275.