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 A215070 Number of squarefree words of length n in an n-ary alphabet, with new values 0..n-1 introduced in increasing order. 0
 1, 1, 2, 4, 12, 40, 154, 660, 3114, 15930, 87645, 514851, 3211220, 21166029, 146849903, 1068808441, 8136559688, 64621235409, 534207882566 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS Diagonal of A215075. LINKS Table of n, a(n) for n=1..19. EXAMPLE Some solutions for n=6: ..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 ..2....2....2....0....0....2....2....0....2....0....0....2....2....0....2....2 ..1....1....3....2....2....0....3....2....3....2....2....3....3....2....1....1 ..0....0....0....3....1....1....4....3....4....0....3....2....1....3....0....3 ..1....3....2....0....0....3....5....4....0....1....2....0....2....1....2....4 CROSSREFS Sequence in context: A268010 A215073 A215074 * A188479 A062962 A033472 Adjacent sequences: A215067 A215068 A215069 * A215071 A215072 A215073 KEYWORD nonn AUTHOR R. H. Hardin, Aug 02 2012 STATUS approved

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Last modified December 7 07:48 EST 2023. Contains 367630 sequences. (Running on oeis4.)