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.

Previous Showing 11-13 of 13 results.

A320764 Number of ordered set partitions of [n] where the maximal block size equals eight.

Original entry on oeis.org

1, 18, 360, 7260, 152460, 3361644, 78041964, 1908389340, 49118959890, 1328964080730, 37738620245898, 1122927974067042, 34953464391146730, 1136306352798186570, 38520124906043253330, 1359621561034260858906, 49896547074800880656202, 1901350452285623246965200
Offset: 8

Views

Author

Alois P. Heinz, Oct 20 2018

Keywords

Crossrefs

Column k=8 of A276922.

Programs

  • Maple
    b:= proc(n, k) option remember; `if`(n=0, 1, add(
          b(n-i, k)*binomial(n, i), i=1..min(n, k)))
        end:
    a:= n-> (k-> b(n, k) -b(n, k-1))(8):
    seq(a(n), n=8..25);

Formula

E.g.f.: 1/(1-Sum_{i=1..8} x^i/i!) - 1/(1-Sum_{i=1..7} x^i/i!).
a(n) = A276928(n) - A276927(n).

A320765 Number of ordered set partitions of [n] where the maximal block size equals nine.

Original entry on oeis.org

1, 20, 440, 9680, 220220, 5229224, 130069940, 3392692160, 92780281880, 2657929522820, 79670485645608, 2495398380120360, 81558207395885220, 2777643033619233780, 98440545801322467600, 3625667341827832048176, 138601954935720474004950, 5492809832014657114548300
Offset: 9

Views

Author

Alois P. Heinz, Oct 20 2018

Keywords

Crossrefs

Column k=9 of A276922.

Programs

  • Maple
    b:= proc(n, k) option remember; `if`(n=0, 1, add(
          b(n-i, k)*binomial(n, i), i=1..min(n, k)))
        end:
    a:= n-> (k-> b(n, k) -b(n, k-1))(9):
    seq(a(n), n=9..25);

Formula

E.g.f.: 1/(1-Sum_{i=1..9} x^i/i!) - 1/(1-Sum_{i=1..8} x^i/i!).
a(n) = A276929(n) - A276928(n).

A320766 Number of ordered set partitions of [n] where the maximal block size equals ten.

Original entry on oeis.org

1, 22, 528, 12584, 308308, 7843836, 208111904, 5767576672, 167004507384, 5050066185736, 159340977018652, 5240336900883084, 179428070995076904, 6388579669849124748, 236257342145458744968, 9064169856705631376280, 360365153529146965326270
Offset: 10

Views

Author

Alois P. Heinz, Oct 20 2018

Keywords

Crossrefs

Column k=10 of A276922.

Programs

  • Maple
    b:= proc(n, k) option remember; `if`(n=0, 1, add(
          b(n-i, k)*binomial(n, i), i=1..min(n, k)))
        end:
    a:= n-> (k-> b(n, k) -b(n, k-1))(10):
    seq(a(n), n=10..30);

Formula

E.g.f.: 1/(1-Sum_{i=1..10} x^i/i!) - 1/(1-Sum_{i=1..9} x^i/i!).
a(n) = A276930(n) - A276929(n).
Previous Showing 11-13 of 13 results.