cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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A292724 Number of multisets of nonempty words with a total of n letters over 9-ary alphabet such that within each word every letter of the alphabet is at least as frequent as the subsequent alphabet letter.

Original entry on oeis.org

1, 1, 4, 14, 67, 343, 2151, 14900, 119259, 1055520, 6837054, 49975756, 358031350, 2673108092, 20399335633, 161247005007, 1321885836686, 10814140769210, 93349395210404, 726371063425227, 5939975798740967, 48195816632614079, 396235068140514442
Offset: 0

Views

Author

Alois P. Heinz, Sep 21 2017

Keywords

Crossrefs

Column k=9 of A292712.

Programs

  • Maple
    b:= proc(n, i, t) option remember; `if`(t=1, 1/n!,
          add(b(n-j, j, t-1)/j!, j=i..n/t))
        end:
    a:= proc(n) option remember; `if`(n=0, 1, add(add(d*d!*
          b(d, 0, 9), d=numtheory[divisors](j))*a(n-j), j=1..n)/n)
        end:
    seq(a(n), n=0..35);

Formula

G.f.: Product_{j>=1} 1/(1-x^j)^A226879(j).
Euler transform of A226879.

A292725 Number of multisets of nonempty words with a total of n letters over 10-ary alphabet such that within each word every letter of the alphabet is at least as frequent as the subsequent alphabet letter.

Original entry on oeis.org

1, 1, 4, 14, 67, 343, 2151, 14900, 119259, 1055520, 10465854, 73562956, 592088950, 4560084092, 37322365393, 303133205967, 2640424710926, 22786686453050, 210764523790244, 1891228958070987, 18197644702881767, 155143878113188799, 1411297482751989322
Offset: 0

Views

Author

Alois P. Heinz, Sep 21 2017

Keywords

Crossrefs

Column k=10 of A292712.

Programs

  • Maple
    b:= proc(n, i, t) option remember; `if`(t=1, 1/n!,
          add(b(n-j, j, t-1)/j!, j=i..n/t))
        end:
    a:= proc(n) option remember; `if`(n=0, 1, add(add(d*d!*
          b(d, 0, 10), d=numtheory[divisors](j))*a(n-j), j=1..n)/n)
        end:
    seq(a(n), n=0..35);

Formula

G.f.: Product_{j>=1} 1/(1-x^j)^A226880(j).
Euler transform of A226880.
Previous Showing 11-12 of 12 results.