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A293968 Number of sets of exactly six nonempty words with a total of n letters over n-ary alphabet such that within each prefix of a word every letter of the alphabet is at least as frequent as the subsequent alphabet letter. 2
4, 62, 417, 2414, 12190, 57686, 260349, 1143710, 4936266, 21117128, 90035798, 384416432, 1649398948, 7133455202, 31173583589, 137947781614, 619247938106, 2824375268432, 13105785174035, 61940904739132, 298438345898409, 1466892183248186, 7358885205363735 (list; graph; refs; listen; history; text; internal format)
OFFSET

14,1

LINKS

Alois P. Heinz, Table of n, a(n) for n = 14..810

FORMULA

a(n) = [x^n y^6] Product_{j>=1} (1+y*x^j)^A000085(j).

MAPLE

g:= proc(n) option remember; `if`(n<2, 1, g(n-1)+(n-1)*g(n-2)) end:

b:= proc(n, i) option remember; series(`if`(n=0, 1, `if`(i<1, 0,

      add(b(n-i*j, i-1)*binomial(g(i), j)*x^j, j=0..n/i))), x, 7)

    end:

a:= n-> coeff(b(n$2), x, 6):

seq(a(n), n=14..40);

CROSSREFS

Column k=6 of A293815.

Cf. A000085.

Sequence in context: A102193 A232156 A316391 * A222791 A166028 A241997

Adjacent sequences:  A293965 A293966 A293967 * A293969 A293970 A293971

KEYWORD

nonn

AUTHOR

Alois P. Heinz, Oct 20 2017

STATUS

approved

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Last modified January 20 21:46 EST 2022. Contains 350472 sequences. (Running on oeis4.)