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A213876
Number of words w where each letter of the 6-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, 720, 10395, 3864040, 4622269345, 10915151070941, 40684710729862072, 211109968702038259993, 1409438188685787895321841, 11481253272835564584899247346, 109898940874611419792791074271620, 1202306852636261419990922606451803760
OFFSET
0,2
EXAMPLE
a(0) = 1: the empty word.
a(1) = 720: abcdef, abcdfe, abcedf, ..., fedbca, fedcab, fedcba.
a(2) = 10395: aabbccddeeff, aabbccddefef, aabbccddfeef, ..., fedcaabbcdef, fedcababcdef, fedcbaabcdef.
CROSSREFS
Column k=6 of A213275.
Sequence in context: A052792 A052790 A052521 * A052785 A052783 A112002
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Jun 23 2012
STATUS
approved