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 A261857 Number of compositions of n into distinct parts where each part i is marked with a word of length i over a senary alphabet whose letters appear in alphabetical order and all letters occur at least once in the composition. 2
 403, 3090, 26523, 178456, 4328268, 11655792, 55380132, 203857488, 908020203, 15089942326, 32659354659, 119798424120, 366557119686, 1229877368940, 4069268482608, 64750089252368, 122070519766665, 408439013722194, 1090232738714433, 3275624230408044 (list; graph; refs; listen; history; text; internal format)
 OFFSET 6,1 COMMENTS Also number of matrices with six rows of nonnegative integer entries and without zero rows or columns such that the sum of all entries is equal to n and the column sums are distinct. LINKS Alois P. Heinz, Table of n, a(n) for n = 6..2500 FORMULA a(n) = A261836(n,6). MAPLE b:= proc(n, i, p, k) option remember;       `if`(i*(i+1)/2n, 0, b(n-i, i-1, p+1, k)*binomial(i+k-1, k-1))))     end: a:= n->(k->add(b(n\$2, 0, k-i)*(-1)^i*binomial(k, i), i=0..k))(6): seq(a(n), n=6..30); CROSSREFS Column k=6 of A261836. Sequence in context: A213605 A083815 A250893 * A165808 A283662 A097741 Adjacent sequences:  A261854 A261855 A261856 * A261858 A261859 A261860 KEYWORD nonn AUTHOR Alois P. Heinz, Sep 03 2015 STATUS approved

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Last modified February 25 02:54 EST 2020. Contains 332217 sequences. (Running on oeis4.)