A213878 Number of words w where each letter of the 8-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, 40320, 2027025, 13681123135, 551211090935595, 64157120593526429971, 15388200323143520006870562, 6273648300104128965616586081511, 3847028733161627562733350467148495403, 3264601141014490309682718148875987514642243

Offset

0,2

Links

Table of n, a(n) for n=0..9.

Example

a(0) = 1: the empty word.
a(1) = 40320: abcdefgh, abcdefhg, abcdegfh, ..., hgfedbca, hgfedcab, hgfedcba, (all permutations of 8 letters).

Crossrefs

Column k=8 of A213275.

Sequence in context: A133068 A254081 A228911 * A179063 A246196 A246616

Adjacent sequences: A213875 A213876 A213877 * A213879 A213880 A213881

Keyword

nonn

Author

Alois P. Heinz, Jun 23 2012

Status

approved