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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A157156 Triangle T(n, k, m) = (m*(n-k) + 1)*T(n-1, k-1, m) + (m*k + 1)*T(n-1, k, m) - m*k*(n-k)*T(n-2, k-1, m) with T(n, 0, m) = T(n, n, m) = 1 and m = 5, read by rows.

Original entry on oeis.org

1, 1, 1, 1, 7, 1, 1, 43, 43, 1, 1, 259, 806, 259, 1, 1, 1555, 11720, 11720, 1555, 1, 1, 9331, 151215, 338770, 151215, 9331, 1, 1, 55987, 1828221, 7892635, 7892635, 1828221, 55987, 1, 1, 335923, 21286168, 162474781, 304389070, 162474781, 21286168, 335923, 1
Offset: 0

Views

Author

Roger L. Bagula, Feb 24 2009

Keywords

Examples

			Triangle begins as:
  1;
  1,      1;
  1,      7,        1;
  1,     43,       43,         1;
  1,    259,      806,       259,         1;
  1,   1555,    11720,     11720,      1555,         1;
  1,   9331,   151215,    338770,    151215,      9331,        1;
  1,  55987,  1828221,   7892635,   7892635,   1828221,    55987,      1;
  1, 335923, 21286168, 162474781, 304389070, 162474781, 21286168, 335923, 1;
		

Crossrefs

Programs

  • Mathematica
    T[n_, k_, m_]:= T[n, k, m]= If[k==0 || k==n, 1, (m*(n-k)+1)*T[n-1,k-1,m] + (m*k+1)*T[n-1,k,m] - m*k*(n-k)*T[n-2,k-1,m]];
    Table[T[n,k,5], {n,0,10}, {k,0,n}]//Flatten (* modified by G. C. Greubel, Jan 10 2022 *)
  • Sage
    @CachedFunction
    def T(n,k,m):  # A157156
        if (k==0 or k==n): return 1
        else: return (m*(n-k) +1)*T(n-1,k-1,m) + (m*k+1)*T(n-1,k,m) - m*k*(n-k)*T(n-2,k-1,m)
    flatten([[T(n,k,5) for k in (0..n)] for n in (0..20)]) # G. C. Greubel, Jan 10 2022

Formula

T(n, k, m) = (m*(n-k) + 1)*T(n-1, k-1, m) + (m*k + 1)*T(n-1, k, m) - m*k*(n-k)*T(n-2, k-1, m) with T(n, 0, m) = T(n, n, m) = 1 and m = 5.
T(n, n-k, m) = T(n, k, m).
T(n, 1, 5) = A003464(n). - G. C. Greubel, Jan 10 2022

Extensions

Edited by G. C. Greubel, Jan 10 2022

A157207 Triangle T(n, k, m) = (m*(n-k) + 1)*T(n-1, k-1, m) + (m*k + 1)*T(n-1, k, m) + m*f(n,k)*T(n-2, k-1, m) with T(n, 0, m) = T(n, n, m) = 1, f(n, k) = k if k <= floor(n/2) otherwise n-k, and m = 1, read by rows.

Original entry on oeis.org

1, 1, 1, 1, 5, 1, 1, 14, 14, 1, 1, 33, 94, 33, 1, 1, 72, 442, 442, 72, 1, 1, 151, 1752, 3818, 1752, 151, 1, 1, 310, 6306, 25358, 25358, 6306, 310, 1, 1, 629, 21390, 144524, 268852, 144524, 21390, 629, 1, 1, 1268, 69822, 746744, 2312836, 2312836, 746744, 69822, 1268, 1
Offset: 0

Views

Author

Roger L. Bagula, Feb 25 2009

Keywords

Examples

			Triangle begins as:
  1;
  1,    1;
  1,    5,     1;
  1,   14,    14,      1;
  1,   33,    94,     33,       1;
  1,   72,   442,    442,      72,       1;
  1,  151,  1752,   3818,    1752,     151,      1;
  1,  310,  6306,  25358,   25358,    6306,    310,     1;
  1,  629, 21390, 144524,  268852,  144524,  21390,   629,    1;
  1, 1268, 69822, 746744, 2312836, 2312836, 746744, 69822, 1268, 1;
		

Crossrefs

Programs

  • Mathematica
    f[n_,k_]:= If[k<=Floor[n/2], k, n-k];
    T[n_, k_, m_]:= T[n, k, m]= If[k==0 || k==n, 1, (m*(n-k)+1)*T[n-1,k-1,m] + (m*k+1)*T[n-1,k,m] + m*f[n,k]*T[n-2,k-1,m]];
    Table[T[n,k,1], {n,0,10}, {k,0,n}]//Flatten (* modified by G. C. Greubel, Jan 10 2022 *)
  • Sage
    def f(n,k): return k if (k <= n//2) else n-k
    @CachedFunction
    def T(n,k,m):  # A157207
        if (k==0 or k==n): return 1
        else: return (m*(n-k) +1)*T(n-1,k-1,m) + (m*k+1)*T(n-1,k,m) + m*f(n,k)*T(n-2,k-1,m)
    flatten([[T(n,k,1) for k in (0..n)] for n in (0..20)]) # G. C. Greubel, Jan 10 2022

Formula

T(n, k, m) = (m*(n-k) + 1)*T(n-1, k-1, m) + (m*k + 1)*T(n-1, k, m) + m*f(n,k)*T(n-2, k-1, m) with T(n, 0, m) = T(n, n, m) = 1, f(n, k) = k if k <= floor(n/2) otherwise n-k, and m = 1.
T(n, n-k, m) = T(n, k, m).
T(n, 1, 1) = A094002(n-1). - G. C. Greubel, Jan 10 2022

Extensions

Edited by G. C. Greubel, Jan 10 2022

A157208 Triangle T(n, k, m) = (m*(n-k) + 1)*T(n-1, k-1, m) + (m*k + 1)*T(n-1, k, m) + m*f(n,k)*T(n-2, k-1, m) with T(n, 0, m) = T(n, n, m) = 1, f(n, k) = k if k <= floor(n/2) otherwise n-k, and m = 2, read by rows.

Original entry on oeis.org

1, 1, 1, 1, 8, 1, 1, 31, 31, 1, 1, 102, 342, 102, 1, 1, 317, 2548, 2548, 317, 1, 1, 964, 16001, 37724, 16001, 964, 1, 1, 2907, 91877, 423365, 423365, 91877, 2907, 1, 1, 8738, 501032, 4070208, 7922362, 4070208, 501032, 8738, 1, 1, 26233, 2647858, 35556134, 119460466, 119460466, 35556134, 2647858, 26233, 1
Offset: 0

Views

Author

Roger L. Bagula, Feb 25 2009

Keywords

Examples

			Triangle begins as:
  1;
  1,    1;
  1,    8,      1;
  1,   31,     31,       1;
  1,  102,    342,     102,       1;
  1,  317,   2548,    2548,     317,       1;
  1,  964,  16001,   37724,   16001,     964,      1;
  1, 2907,  91877,  423365,  423365,   91877,   2907,    1;
  1, 8738, 501032, 4070208, 7922362, 4070208, 501032, 8738, 1;
		

Crossrefs

Programs

  • Mathematica
    f[n_,k_]:= If[k<=Floor[n/2], k, n-k];
    T[n_, k_, m_]:= T[n, k, m]= If[k==0 || k==n, 1, (m*(n-k)+1)*T[n-1,k-1,m] + (m*k+1)*T[n-1,k,m] + m*f[n,k]*T[n-2,k-1,m]];
    Table[T[n,k,2], {n,0,10}, {k,0,n}]//Flatten (* modified by G. C. Greubel, Jan 10 2022 *)
  • Sage
    def f(n,k): return k if (k <= n//2) else n-k
    @CachedFunction
    def T(n,k,m):  # A157208
        if (k==0 or k==n): return 1
        else: return (m*(n-k) +1)*T(n-1,k-1,m) + (m*k+1)*T(n-1,k,m) + m*f(n,k)*T(n-2,k-1,m)
    flatten([[T(n,k,2) for k in (0..n)] for n in (0..20)]) # G. C. Greubel, Jan 10 2022

Formula

T(n, k, m) = (m*(n-k) + 1)*T(n-1, k-1, m) + (m*k + 1)*T(n-1, k, m) + m*f(n,k)*T(n-2, k-1, m) with T(n, 0, m) = T(n, n, m) = 1, f(n, k) = k if k <= floor(n/2) otherwise n-k, and m = 2.
T(n, n-k, m) = T(n, k, m).

Extensions

Edited by G. C. Greubel, Jan 10 2022

A157209 Triangle T(n, k, m) = (m*(n-k) + 1)*T(n-1, k-1, m) + (m*k + 1)*T(n-1, k, m) + m*f(n,k)*T(n-2, k-1, m) with T(n, 0, m) = T(n, n, m) = 1, f(n, k) = k if k <= floor(n/2) otherwise n-k, and m = 3, read by rows.

Original entry on oeis.org

1, 1, 1, 1, 11, 1, 1, 54, 54, 1, 1, 229, 822, 229, 1, 1, 932, 8368, 8368, 932, 1, 1, 3747, 72066, 174758, 72066, 3747, 1, 1, 15010, 570006, 2759750, 2759750, 570006, 15010, 1, 1, 60065, 4297714, 37366190, 73850596, 37366190, 4297714, 60065, 1, 1, 240288, 31495488, 460448520, 1591033788, 1591033788, 460448520, 31495488, 240288, 1
Offset: 0

Views

Author

Roger L. Bagula, Feb 25 2009

Keywords

Examples

			Triangle begins as:
  1;
  1,     1;
  1,    11,       1;
  1,    54,      54,        1;
  1,   229,     822,      229,        1;
  1,   932,    8368,     8368,      932,        1;
  1,  3747,   72066,   174758,    72066,     3747,       1;
  1, 15010,  570006,  2759750,  2759750,   570006,   15010,     1;
  1, 60065, 4297714, 37366190, 73850596, 37366190, 4297714, 60065, 1;
		

Crossrefs

Programs

  • Mathematica
    f[n_,k_]:= If[k<=Floor[n/2], k, n-k];
    T[n_, k_, m_]:= T[n, k, m]= If[k==0 || k==n, 1, (m*(n-k)+1)*T[n-1,k-1,m] + (m*k+1)*T[n-1,k,m] + m*f[n,k]*T[n-2,k-1,m]];
    Table[T[n,k,3], {n,0,10}, {k,0,n}]//Flatten (* modified by G. C. Greubel, Jan 10 2022 *)
  • Sage
    def f(n,k): return k if (k <= n//2) else n-k
    @CachedFunction
    def T(n,k,m):  # A157209
        if (k==0 or k==n): return 1
        else: return (m*(n-k) +1)*T(n-1,k-1,m) + (m*k+1)*T(n-1,k,m) + m*f(n,k)*T(n-2,k-1,m)
    flatten([[T(n,k,3) for k in (0..n)] for n in (0..20)]) # G. C. Greubel, Jan 10 2022

Formula

T(n, k, m) = (m*(n-k) + 1)*T(n-1, k-1, m) + (m*k + 1)*T(n-1, k, m) + m*f(n,k)*T(n-2, k-1, m) with T(n, 0, m) = T(n, n, m) = 1, f(n, k) = k if k <= floor(n/2) otherwise n-k, and m = 3.
T(n, n-k, m) = T(n, k, m).

Extensions

Edited by G. C. Greubel, Jan 10 2022

A157210 Triangle T(n, k, m) = (m*(n-k) + 1)*T(n-1, k-1, m) + (m*k + 1)*T(n-1, k, m) - m*f(n,k)*T(n-2, k-1, m) with T(n, 0, m) = T(n, n, m) = 1, f(n, k) = k if k <= floor(n/2) otherwise n-k, and m = 1, read by rows.

Original entry on oeis.org

1, 1, 1, 1, 3, 1, 1, 8, 8, 1, 1, 19, 42, 19, 1, 1, 42, 186, 186, 42, 1, 1, 89, 730, 1362, 730, 89, 1, 1, 184, 2640, 8540, 8540, 2640, 184, 1, 1, 375, 9030, 47810, 79952, 47810, 9030, 375, 1, 1, 758, 29722, 246530, 652460, 652460, 246530, 29722, 758, 1
Offset: 0

Views

Author

Roger L. Bagula, Feb 25 2009

Keywords

Examples

			Triangle begins as:
  1;
  1,    1;
  1,    3,     1;
  1,    8,     8,       1;
  1,   19,    42,      19,       1;
  1,   42,   186,     186,      42,       1;
  1,   89,   730,    1362,     730,      89,       1;
  1,  184,  2640,    8540,    8540,    2640,     184,       1;
  1,  375,  9030,   47810,   79952,   47810,    9030,     375,     1;
  1,  758, 29722,  246530,  652460,  652460,  246530,   29722,   758,    1;
  1, 1525, 95238, 1196806, 4796770, 7429760, 4796770, 1196806, 95238, 1525, 1;
		

Crossrefs

Programs

  • Mathematica
    f[n_,k_]:= If[k<=Floor[n/2], k, n-k];
    T[n_, k_, m_]:= T[n, k, m]= If[k==0 || k==n, 1, (m*(n-k)+1)*T[n-1,k-1,m] + (m*k+1)*T[n-1,k,m] - m*f[n,k]*T[n-2,k-1,m]];
    Table[T[n,k,1], {n,0,10}, {k,0,n}]//Flatten (* modified by G. C. Greubel, Jan 10 2022 *)
  • Sage
    def f(n,k): return k if (k <= n//2) else n-k
    @CachedFunction
    def T(n,k,m):  # A157210
        if (k==0 or k==n): return 1
        else: return (m*(n-k) +1)*T(n-1,k-1,m) + (m*k+1)*T(n-1,k,m) - m*f(n,k)*T(n-2,k-1,m)
    flatten([[T(n,k,1) for k in (0..n)] for n in (0..20)]) # G. C. Greubel, Jan 10 2022

Formula

T(n, k, m) = (m*(n-k) + 1)*T(n-1, k-1, m) + (m*k + 1)*T(n-1, k, m) - m*f(n,k)*T(n-2, k-1, m) with T(n, 0, m) = T(n, n, m) = 1, f(n, k) = k if k <= floor(n/2) otherwise n-k, and m = 1.
T(n, n-k, m) = T(n, k, m).
T(n, 1, 1) = A079583(n-1). - G. C. Greubel, Jan 10 2022

Extensions

Edited by G. C. Greubel, Jan 10 2022

A157212 Triangle T(n, k, m) = (m*(n-k) + 1)*T(n-1, k-1, m) + (m*k + 1)*T(n-1, k, m) - m*f(n,k)*T(n-2, k-1, m) with T(n, 0, m) = T(n, n, m) = 1, f(n, k) = k if k <= floor(n/2) otherwise n-k, and m = 3, read by rows.

Original entry on oeis.org

1, 1, 1, 1, 5, 1, 1, 24, 24, 1, 1, 103, 306, 103, 1, 1, 422, 3028, 3028, 422, 1, 1, 1701, 26064, 57806, 26064, 1701, 1, 1, 6820, 207132, 889640, 889640, 207132, 6820, 1, 1, 27299, 1569298, 11975936, 22436968, 11975936, 1569298, 27299, 1, 1, 109218, 11544744, 147711834, 472619880, 472619880, 147711834, 11544744, 109218, 1
Offset: 0

Views

Author

Roger L. Bagula, Feb 25 2009

Keywords

Examples

			Triangle begins as:
  1;
  1,     1;
  1,     5,       1;
  1,    24,      24,        1;
  1,   103,     306,      103,        1;
  1,   422,    3028,     3028,      422,        1;
  1,  1701,   26064,    57806,    26064,     1701,       1;
  1,  6820,  207132,   889640,   889640,   207132,    6820,     1;
  1, 27299, 1569298, 11975936, 22436968, 11975936, 1569298, 27299, 1;
		

Crossrefs

Programs

  • Mathematica
    f[n_,k_]:= If[k<=Floor[n/2], k, n-k];
    T[n_, k_, m_]:= T[n, k, m]= If[k==0 || k==n, 1, (m*(n-k)+1)*T[n-1,k-1,m] + (m*k+1)*T[n-1,k,m] - m*f[n,k]*T[n-2,k-1,m]];
    Table[T[n,k,3], {n,0,12}, {k,0,n}]//Flatten (* modified by G. C. Greubel, Jan 10 2022 *)
  • Sage
    def f(n,k): return k if (k <= n//2) else n-k
    @CachedFunction
    def T(n,k,m):  # A157212
        if (k==0 or k==n): return 1
        else: return (m*(n-k) +1)*T(n-1,k-1,m) + (m*k+1)*T(n-1,k,m) - m*f(n,k)*T(n-2,k-1,m)
    flatten([[T(n,k,3) for k in (0..n)] for n in (0..12)]) # G. C. Greubel, Jan 10 2022

Formula

T(n, k, m) = (m*(n-k) + 1)*T(n-1, k-1, m) + (m*k + 1)*T(n-1, k, m) - m*f(n,k)*T(n-2, k-1, m) with T(n, 0, m) = T(n, n, m) = 1, f(n, k) = k if k <= floor(n/2) otherwise n-k, and m = 3.
T(n, n-k, m) = T(n, k, m).

Extensions

Edited by G. C. Greubel, Jan 10 2022

A157268 Triangle T(n, k, m) = (m*(n-k) + 1)*T(n-1, k-1, m) + (m*k + 1)*T(n-1, k, m) + m*f(n,k)*T(n-2, k-1, m) with T(n, 0, m) = T(n, n, m) = 1, f(n, k) = 2^k if k <= floor(n/2) otherwise 2^(n-k), and m = 1, read by rows.

Original entry on oeis.org

1, 1, 1, 1, 6, 1, 1, 17, 17, 1, 1, 40, 126, 40, 1, 1, 87, 606, 606, 87, 1, 1, 182, 2413, 5856, 2413, 182, 1, 1, 373, 8679, 40337, 40337, 8679, 373, 1, 1, 756, 29376, 232726, 497066, 232726, 29376, 756, 1, 1, 1523, 95668, 1205968, 4527078, 4527078, 1205968, 95668, 1523, 1
Offset: 0

Views

Author

Roger L. Bagula, Feb 26 2009

Keywords

Examples

			Triangle begins as:
  1;
  1,    1;
  1,    6,     1;
  1,   17,    17,       1;
  1,   40,   126,      40,       1;
  1,   87,   606,     606,      87,       1;
  1,  182,  2413,    5856,    2413,     182,       1;
  1,  373,  8679,   40337,   40337,    8679,     373,     1;
  1,  756, 29376,  232726,  497066,  232726,   29376,   756,    1;
  1, 1523, 95668, 1205968, 4527078, 4527078, 1205968, 95668, 1523, 1;
		

Crossrefs

Programs

  • Mathematica
    f[n_,k_]:= If[k<=Floor[n/2], 2^k, 2^(n-k)];
    T[n_, k_, m_]:= T[n, k, m]= If[k==0 || k==n, 1, (m*(n-k)+1)*T[n-1,k-1,m] + (m*k+1)*T[n-1,k,m] + m*f[n,k]*T[n-2,k-1,m]];
    Table[T[n,k,1], {n,0,12}, {k,0,n}]//Flatten (* modified by G. C. Greubel, Feb 04 2022 *)
  • Sage
    def f(n,k): return 2^k if (k <= n//2) else 2^(n-k)
    @CachedFunction
    def T(n,k,m):  # A157207
        if (k==0 or k==n): return 1
        else: return (m*(n-k) +1)*T(n-1,k-1,m) + (m*k+1)*T(n-1,k,m) + m*f(n,k)*T(n-2,k-1,m)
    flatten([[T(n,k,1) for k in (0..n)] for n in (0..12)]) # G. C. Greubel, Feb 04 2022

Formula

T(n, k, m) = (m*(n-k) + 1)*T(n-1, k-1, m) + (m*k + 1)*T(n-1, k, m) + m*f(n,k)*T(n-2, k-1, m) with T(n, 0, m) = T(n, n, m) = 1, f(n, k) = 2^k if k <= floor(n/2) otherwise 2^(n-k), and m = 1.
T(n, n-k, m) = T(n, k, m).
T(n, 1, 1) = A101945(n-1), n >= 1. - G. C. Greubel, Feb 04 2022

Extensions

Edited by G. C. Greubel, Feb 04 2022

A157272 Triangle T(n, k, m) = (m*(n-k) + 1)*T(n-1, k-1, m) + (m*k + 1)*T(n-1, k, m) + m*f(n,k)*T(n-2, k-1, m) with T(n, 0, m) = T(n, n, m) = 1, f(n, k) = 2*k+1 if k <= floor(n/2) otherwise 2*(n-k)+1, and m = 1, read by rows.

Original entry on oeis.org

1, 1, 1, 1, 7, 1, 1, 20, 20, 1, 1, 47, 155, 47, 1, 1, 102, 753, 753, 102, 1, 1, 213, 3004, 7109, 3004, 213, 1, 1, 436, 10800, 48727, 48727, 10800, 436, 1, 1, 883, 36517, 280736, 551251, 280736, 36517, 883, 1, 1, 1778, 118795, 1454163, 4879214, 4879214, 1454163, 118795, 1778, 1
Offset: 0

Views

Author

Roger L. Bagula, Feb 26 2009

Keywords

Examples

			Triangle begins as:
  1;
  1,    1;
  1,    7,      1;
  1,   20,     20,       1;
  1,   47,    155,      47,       1;
  1,  102,    753,     753,     102,       1;
  1,  213,   3004,    7109,    3004,     213,       1;
  1,  436,  10800,   48727,   48727,   10800,     436,      1;
  1,  883,  36517,  280736,  551251,  280736,   36517,    883,    1;
  1, 1778, 118795, 1454163, 4879214, 4879214, 1454163, 118795, 1778, 1;
		

Crossrefs

Programs

  • Mathematica
    f[n_,k_]:= If[k<=Floor[n/2], 2*k+1, 2*(n-k)+1];
    T[n_, k_, m_]:= T[n, k, m]= If[k==0 || k==n, 1, (m*(n-k)+1)*T[n-1,k-1,m] + (m*k+1)*T[n-1,k,m] + m*f[n,k]*T[n-2,k-1,m]];
    Table[T[n,k,1], {n,0,12}, {k,0,n}]//Flatten (* modified by G. C. Greubel, Feb 04 2022 *)
  • Sage
    def f(n,k): return 2*k+1 if (k <= n//2) else 2*(n-k)+1
    @CachedFunction
    def T(n,k,m):  # A157207
        if (k==0 or k==n): return 1
        else: return (m*(n-k) +1)*T(n-1,k-1,m) + (m*k+1)*T(n-1,k,m) + m*f(n,k)*T(n-2,k-1,m)
    flatten([[T(n,k,1) for k in (0..n)] for n in (0..12)]) # G. C. Greubel, Feb 04 2022

Formula

T(n, k, m) = (m*(n-k) + 1)*T(n-1, k-1, m) + (m*k + 1)*T(n-1, k, m) + m*f(n,k)*T(n-2, k-1, m) with T(n, 0, m) = T(n, n, m) = 1, f(n, k) = 2*k+1 if k <= floor(n/2) otherwise 2*(n-k)+1, and m = 1.
T(n, n-k, m) = T(n, k, m).

Extensions

Edited by G. C. Greubel, Feb 04 2022

A157274 Triangle T(n, k, m) = (m*(n-k) + 1)*T(n-1, k-1, m) + (m*k + 1)*T(n-1, k, m) + m*f(n,k)*T(n-2, k-1, m) with T(n, 0, m) = T(n, n, m) = 1, f(n, k) = 2*k+1 if k <= floor(n/2) otherwise 2*(n-k)+1, and m = 3, read by rows.

Original entry on oeis.org

1, 1, 1, 1, 17, 1, 1, 84, 84, 1, 1, 355, 1431, 355, 1, 1, 1442, 14827, 14827, 1442, 1, 1, 5793, 127860, 326591, 127860, 5793, 1, 1, 23200, 1009338, 5239457, 5239457, 1009338, 23200, 1, 1, 92831, 7593061, 71229038, 145043839, 71229038, 7593061, 92831, 1
Offset: 0

Views

Author

Roger L. Bagula, Feb 26 2009

Keywords

Examples

			Triangle begins as:
  1;
  1,     1;
  1,    17,       1;
  1,    84,      84,        1;
  1,   355,    1431,      355,         1;
  1,  1442,   14827,    14827,      1442,        1;
  1,  5793,  127860,   326591,    127860,     5793,       1;
  1, 23200, 1009338,  5239457,   5239457,  1009338,   23200,     1;
  1, 92831, 7593061, 71229038, 145043839, 71229038, 7593061, 92831, 1;
		

Crossrefs

Programs

  • Mathematica
    f[n_,k_]:= If[k<=Floor[n/2], 2*k+1, 2*(n-k)+1];
    T[n_, k_, m_]:= T[n, k, m]= If[k==0 || k==n, 1, (m*(n-k)+1)*T[n-1,k-1,m] + (m*k+1)*T[n-1,k,m] + m*f[n,k]*T[n-2,k-1,m]];
    Table[T[n,k,3], {n,0,12}, {k,0,n}]//Flatten (* modified by G. C. Greubel, Feb 05 2022 *)
  • Sage
    def f(n,k): return 2*k+1 if (k <= n//2) else 2*(n-k)+1
    @CachedFunction
    def T(n,k,m):  # A157207
        if (k==0 or k==n): return 1
        else: return (m*(n-k) +1)*T(n-1,k-1,m) + (m*k+1)*T(n-1,k,m) + m*f(n,k)*T(n-2,k-1,m)
    flatten([[T(n,k,3) for k in (0..n)] for n in (0..12)]) # G. C. Greubel, Feb 05 2022

Formula

T(n, k, m) = (m*(n-k) + 1)*T(n-1, k-1, m) + (m*k + 1)*T(n-1, k, m) + m*f(n,k)*T(n-2, k-1, m) with T(n, 0, m) = T(n, n, m) = 1, f(n, k) = 2*k+1 if k <= floor(n/2) otherwise 2*(n-k)+1, and m = 3.
T(n, n-k, m) = T(n, k, m).

Extensions

Edited by G. C. Greubel, Feb 05 2022

A157275 Triangle T(n, k, m) = (m*(n-k) + 1)*T(n-1, k-1, m) + (m*k + 1)*T(n-1, k, m) + m*f(n,k)*T(n-2, k-1, m) with T(n, 0, m) = T(n, n, m) = 1, f(n, k) = 2*k if k <= floor(n/2) otherwise 2*(n-k), and m = 1, read by rows.

Original entry on oeis.org

1, 1, 1, 1, 6, 1, 1, 17, 17, 1, 1, 40, 126, 40, 1, 1, 87, 606, 606, 87, 1, 1, 182, 2413, 5604, 2413, 182, 1, 1, 373, 8679, 38117, 38117, 8679, 373, 1, 1, 756, 29376, 219020, 426002, 219020, 29376, 756, 1, 1, 1523, 95668, 1133786, 3749066, 3749066, 1133786, 95668, 1523, 1
Offset: 0

Views

Author

Roger L. Bagula, Feb 26 2009

Keywords

Examples

			Triangle begins as:
  1;
  1,    1;
  1,    6,     1;
  1,   17,    17,       1;
  1,   40,   126,      40,       1;
  1,   87,   606,     606,      87,       1;
  1,  182,  2413,    5604,    2413,     182,       1;
  1,  373,  8679,   38117,   38117,    8679,     373,     1;
  1,  756, 29376,  219020,  426002,  219020,   29376,   756,    1;
  1, 1523, 95668, 1133786, 3749066, 3749066, 1133786, 95668, 1523, 1;
		

Crossrefs

Programs

  • Mathematica
    f[n_,k_]:= If[k<=Floor[n/2], 2*k, 2*(n-k)];
    T[n_, k_, m_]:= T[n, k, m]= If[k==0 || k==n, 1, (m*(n-k)+1)*T[n-1,k-1,m] + (m*k+1)*T[n-1,k,m] + m*f[n,k]*T[n-2,k-1,m]];
    Table[T[n,k,1], {n,0,12}, {k,0,n}]//Flatten (* modified by G. C. Greubel, Feb 05 2022 *)
  • Sage
    def f(n,k): return 2*k if (k <= n//2) else 2*(n-k)
    @CachedFunction
    def T(n,k,m):  # A157275
        if (k==0 or k==n): return 1
        else: return (m*(n-k) +1)*T(n-1,k-1,m) + (m*k+1)*T(n-1,k,m) + m*f(n,k)*T(n-2,k-1,m)
    flatten([[T(n,k,1) for k in (0..n)] for n in (0..12)]) # G. C. Greubel, Feb 05 2022

Formula

T(n, k, m) = (m*(n-k) + 1)*T(n-1, k-1, m) + (m*k + 1)*T(n-1, k, m) + m*f(n,k)*T(n-2, k-1, m) with T(n, 0, m) = T(n, n, m) = 1, f(n, k) = 2*k if k <= floor(n/2) otherwise 2*(n-k), and m = 1.
T(n, n-k, m) = T(n, k, m).
T(n, 1, 1) = A101945(n-1), for n >= 1. - G. C. Greubel, Feb 05 2022

Extensions

Edited by G. C. Greubel, Feb 05 2022
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