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A261777 Number of compositions of n where the (possibly scattered) maximal subsequence of part i with multiplicity j is marked with i words of length j over an n-ary alphabet whose letters appear in alphabetical order and all n letters occur exactly once in the composition. 2
1, 1, 3, 19, 115, 951, 10281, 116313, 1436499, 20203795, 338834053, 5824666893, 108142092169, 2118605140237, 44375797806315, 1039641056342619, 25413053107195539, 646983321301050147, 17311013062443870681, 481282277347815404745, 13913039361920333694165 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Alois P. Heinz, Table of n, a(n) for n = 0..400

EXAMPLE

a(3) = 19: 3a|b|c, 3a|c|b, 3b|a|c, 3b|c|a, 3c|a|b, 3c|b|a, 2a|b1c, 2b|a1c, 2a|c1b, 2c|a1b, 2b|c1a, 2c|b1a, 1a2b|c, 1a2c|b, 1b2a|c, 1b2c|a, 1c2a|b, 1c2b|a, 111abc.

MAPLE

with(combinat):

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

      b(n-i*j, i-1, p+j)/j!*multinomial(n, n-i*j, j$i), j=0..n/i)))

    end:

a:= n-> b(n$2, 0):

seq(a(n), n=0..25);

CROSSREFS

Cf. A000670, A261774.

Sequence in context: A267802 A229928 A309183 * A037781 A037585 A084133

Adjacent sequences:  A261774 A261775 A261776 * A261778 A261779 A261780

KEYWORD

nonn

AUTHOR

Alois P. Heinz, Aug 31 2015

STATUS

approved

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Last modified July 29 17:05 EDT 2021. Contains 346346 sequences. (Running on oeis4.)