A240613 Number of n-length words w over a 7-ary alphabet such that w is empty or a prefix z concatenated with letter a_i and i=1 or 0 < #(z,a_{i-1}) >= #(z,a_i), where #(z,a_i) counts the occurrences of the i-th letter in z.

1, 1, 2, 5, 14, 46, 165, 651, 2770, 12601, 60686, 305658, 1595454, 8547278, 46685641, 258530476, 1446098060, 8148181066, 46165702543, 262699285827, 1500141404881, 8592741193076, 49353003881425, 284185414898313, 1640366631269049, 9490895165369217

Offset

0,3

Links

Table of n, a(n) for n=0..25.

Crossrefs

Column k=7 of A240608.

Sequence in context: A149898 A240611 A240612 * A240614 A240615 A240616

Adjacent sequences: A240610 A240611 A240612 * A240614 A240615 A240616

Keyword

nonn

Author

Alois P. Heinz, Apr 09 2014

Status

approved