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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A320208 Number of sets of nonempty words with a total of n letters over septenary alphabet such that all letters occur at least once in the set.

Original entry on oeis.org

37633, 1366057, 28969248, 470004045, 6470660266, 79706067707, 906335330250, 9706198156760, 99243640018075, 978284068984075, 9363362648969343, 87485517250169934, 801259222264152813, 7216852772737393058, 64088034265985397794, 562287261308092526759
Offset: 7

Views

Author

Alois P. Heinz, Oct 07 2018

Keywords

Crossrefs

Column k=7 of A319501.
Cf. A320217.

Programs

  • Maple
    h:= proc(n, i, k) option remember; `if`(n=0, 1, `if`(i<1, 0,
          add(h(n-i*j, i-1, k)*binomial(k^i, j), j=0..n/i)))
        end:
    a:= n-> (k-> add((-1)^i*binomial(k, i)*h(n$2, k-i), i=0..k))(7):
    seq(a(n), n=7..25);

A320209 Number of sets of nonempty words with a total of n letters over octonary alphabet such that all letters occur at least once in the set.

Original entry on oeis.org

394353, 18235680, 484092688, 9697863856, 163046201132, 2430540970008, 33194557467204, 424251626739144, 5148887208055692, 59963231946871288, 675318621308265328, 7398542789316786184, 79210967706138213860, 831754864387299725168, 8590788276593760698232
Offset: 8

Views

Author

Alois P. Heinz, Oct 07 2018

Keywords

Crossrefs

Column k=8 of A319501.
Cf. A320218.

Programs

  • Maple
    h:= proc(n, i, k) option remember; `if`(n=0, 1, `if`(i<1, 0,
          add(h(n-i*j, i-1, k)*binomial(k^i, j), j=0..n/i)))
        end:
    a:= n-> (k-> add((-1)^i*binomial(k, i)*h(n$2, k-i), i=0..k))(8):
    seq(a(n), n=8..25);

A320210 Number of sets of nonempty words with a total of n letters over nonary alphabet such that all letters occur at least once in the set.

Original entry on oeis.org

4596553, 263460321, 8549512506, 207037303758, 4169086763787, 73865658618900, 1191183607371897, 17876336340787308, 253521082577243286, 3435636331820210328, 44859666267675306756, 567955878004442678319, 7007036376866803617768, 84571686324119453047650
Offset: 9

Views

Author

Alois P. Heinz, Oct 07 2018

Keywords

Crossrefs

Column k=9 of A319501.
Cf. A320219.

Programs

  • Maple
    h:= proc(n, i, k) option remember; `if`(n=0, 1, `if`(i<1, 0,
          add(h(n-i*j, i-1, k)*binomial(k^i, j), j=0..n/i)))
        end:
    a:= n-> (k-> add((-1)^i*binomial(k, i)*h(n$2, k-i), i=0..k))(9):
    seq(a(n), n=9..25);

A320211 Number of sets of nonempty words with a total of n letters over denary alphabet such that all letters occur at least once in the set.

Original entry on oeis.org

58941091, 4097382940, 159454061270, 4587784661870, 108909499300650, 2259736176893470, 42433681634931005, 737876928284127870, 12073172284265618005, 188049325030487680920, 2812707955072045999940, 40672129029056125818340, 571583937930987524954470
Offset: 10

Views

Author

Alois P. Heinz, Oct 07 2018

Keywords

Crossrefs

Column k=10 of A319501.
Cf. A320220.

Programs

  • Maple
    h:= proc(n, i, k) option remember; `if`(n=0, 1, `if`(i<1, 0,
          add(h(n-i*j, i-1, k)*binomial(k^i, j), j=0..n/i)))
        end:
    a:= n-> (k-> add((-1)^i*binomial(k, i)*h(n$2, k-i), i=0..k))(10):
    seq(a(n), n=10..25);

A320203 Number of sets of nonempty words with a total of n letters over binary alphabet such that all letters occur at least once in the set.

Original entry on oeis.org

3, 12, 38, 110, 302, 806, 2109, 5450, 13917, 35224, 88464, 220608, 546734, 1347290, 3302716, 8057268, 19568800, 47329156, 114025658, 273709580, 654765164, 1561257760, 3711372761, 8797021430, 20794198251, 49024480496, 115292809466, 270495295124, 633186396954
Offset: 2

Views

Author

Alois P. Heinz, Oct 07 2018

Keywords

Examples

			a(2) = 3: {ab}, {ba}, {a,b}.
a(3) = 12: {aab}, {aba}, {abb}, {baa}, {bab}, {bba}, {a,ab}, {a,ba}, {a,bb}, {aa,b}, {ab,b}, {b,ba}.
a(4) = 38: {aaab}, {aaba}, {aabb}, {abaa}, {abab}, {abba}, {abbb}, {baaa}, {baab}, {baba}, {babb}, {bbaa}, {bbab}, {bbba}, {a,aab}, {a,aba}, {a,abb}, {a,baa}, {a,bab}, {a,bba}, {a,bbb}, {aa,ab}, {aa,ba}, {aa,bb}, {aaa,b}, {aab,b}, {ab,ba}, {ab,bb}, {aba,b}, {abb,b}, {b,baa}, {b,bab}, {b,bba}, {ba,bb}, {a,aa,b}, {a,ab,b}, {a,b,ba}, {a,b,bb}.
		

Crossrefs

Column k=2 of A319501.

Programs

  • Maple
    h:= proc(n, i, k) option remember; `if`(n=0, 1, `if`(i<1, 0,
          add(h(n-i*j, i-1, k)*binomial(k^i, j), j=0..n/i)))
        end:
    a:= n-> (k-> add((-1)^i*binomial(k, i)*h(n$2, k-i), i=0..k))(2):
    seq(a(n), n=2..35);
Previous Showing 11-15 of 15 results.