A261842 Number of compositions of n into distinct parts where each part i is marked with a word of length i over a quaternary alphabet whose letters appear in alphabetical order.

1, 4, 10, 100, 195, 736, 6032, 11712, 35285, 100260, 871386, 1492820, 4438573, 10525720, 29825140, 241360728, 405645867, 1086289116, 2489722574, 6158961820, 14573822743, 123303661384, 192326074572, 504783599080, 1073240557055, 2539006453740, 5337585654950

Offset

0,2

Comments

Also matrices with four rows of nonnegative integers with distinct positive column sums and total element sum n.

Links

Alois P. Heinz, Table of n, a(n) for n = 0..5000

Maple

b:= proc(n, i, p) option remember;
      `if`(i*(i+1)/2<n, 0, `if`(n=0, p!, b(n, i-1, p)+
      `if`(i>n, 0, b(n-i, i-1, p+1)*binomial(i+3, 3))))
    end:
a:= n-> b(n$2, 0):
seq(a(n), n=0..40);

Crossrefs

Column k=4 of A261835.

Sequence in context: A266839 A203179 A125855 * A153743 A370987 A245304

Adjacent sequences: A261839 A261840 A261841 * A261843 A261844 A261845

Keyword

nonn

Author

Alois P. Heinz, Sep 03 2015

Status

approved