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A215073
Number of squarefree words of length n in a 7-ary alphabet, with new values 0..6 introduced in increasing order
0
1, 1, 2, 4, 12, 40, 154, 659, 3085, 15438, 81200, 442206, 2465945, 13968206, 79933735, 460447075, 2663586832, 15450089345, 89773528848, 522212524474
OFFSET
1,3
COMMENTS
Column 6 of A215075
EXAMPLE
Some solutions for n=9
..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0
..1....1....1....1....1....1....1....1....1....1....1....1....1....1....1....1
..0....2....2....2....0....2....0....2....0....2....2....0....2....2....2....2
..2....3....3....0....2....3....2....3....2....3....0....2....3....1....0....0
..3....2....0....3....3....2....3....2....0....4....3....3....1....3....2....3
..4....0....4....4....0....4....2....1....3....0....4....4....2....1....1....2
..5....4....5....5....2....2....1....0....1....3....3....3....0....4....2....0
..2....5....2....1....0....3....0....2....2....4....0....5....4....0....3....1
..5....1....4....5....3....2....3....1....1....3....2....6....3....3....4....4
CROSSREFS
Sequence in context: A268954 A268955 A268010 * A215074 A215070 A188479
KEYWORD
nonn
AUTHOR
R. H. Hardin Aug 02 2012
STATUS
approved