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A293732 Number of multisets of nonempty words with a total of n letters over binary alphabet such that within each prefix of a word every letter of the alphabet is at least as frequent as the subsequent alphabet letter. 5
1, 1, 3, 6, 15, 31, 73, 155, 351, 755, 1673, 3604, 7897, 16988, 36902, 79222, 171030, 366180, 786746, 1679976, 3595207, 7657631, 16332935, 34706319, 73812099, 156503351, 332004423, 702533059, 1486998780, 3140716766, 6634315264, 13988517803, 29494816751 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Alois P. Heinz, Table of n, a(n) for n = 0..1000

FORMULA

G.f.: Product_{j>=1} 1/(1-x^j)^A001405(j).

MAPLE

a:= proc(n) option remember; `if`(n=0, 1, add(add(binomial(d,

      floor(d/2))*d, d=numtheory[divisors](j))*a(n-j), j=1..n)/n)

    end:

seq(a(n), n=0..35);

CROSSREFS

Column k=2 of A293108.

Cf. A001405.

Sequence in context: A244706 A097941 A317792 * A117161 A319765 A244707

Adjacent sequences:  A293729 A293730 A293731 * A293733 A293734 A293735

KEYWORD

nonn

AUTHOR

Alois P. Heinz, Oct 15 2017

STATUS

approved

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Last modified May 26 23:51 EDT 2019. Contains 323597 sequences. (Running on oeis4.)