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.

Showing 1-4 of 4 results.

A155871 Subtraction of polynomial coefficients of MacMahon A060187 from third derivative of Pascal's triangle A155863: p(x,n)=(If[n == 0, 1, x^n + 1 + x*D[( x + 1)^(n + 1), {x, 3}]] - 2^n*(1 - x)^(1 + n)*LerchPhi[x, -n, 1/2])/x.

Original entry on oeis.org

1, 1, -16, -110, -16, -117, -1322, -1322, -117, -512, -9703, -22288, -9703, -512, -1843, -58977, -256363, -256363, -58977, -1843, -6048, -328588, -2477728, -4664934, -2477728, -328588, -6048, -18953, -1751300, -21692852, -69388094
Offset: 3

Views

Author

Roger L. Bagula, Jan 29 2009

Keywords

Comments

Row sums are:
{2, -142, -2878, -42718, -634366, -10289662, -185702398, -3715637758,
-81748930558, -1961988796414, -51011749920766}

Examples

			{1, 1},
{-16, -110, -16},
{-117, -1322, -1322, -117},
{-512, -9703, -22288, -9703, -512},
{-1843, -58977, -256363, -256363, -58977, -1843},
{-6048, -328588, -2477728, -4664934, -2477728, -328588, -6048},
{-18953, -1751300, -21692852, -69388094, -69388094, -21692852, -1751300, -18953},
{-58048, -9108221, -178273184, -906867842, -1527023168, -906867842, -178273184, -9108221, -58048},
{-175815, -46690547, -1403033205, -10836712218, -28587853494, -28587853494, -10836712218, -1403033205, -46690547, -175815},
{-529712, -237214810, -10708833968, -121383574287, -477020204064, -743288082732, -477020204064, -121383574287, -10708833968, -237214810, -529712},
{-1592125, -1198358670, -79944129566, -1295922974075, -7310749751463, -16818058154484, -16818058154484, -7310749751463, -1295922974075, -79944129566, -1198358670, -1592125}
		

Crossrefs

Programs

  • Mathematica
    p[x_, n_] = (If[n == 0, 1, x^n + 1 + x*D[(x + 1)^(n + 1), {x, 3}]] - 2^n*(1 - x)^(1 + n)*LerchPhi[x, -n, 1/2])/x;
    Table[FullSimplify[ExpandAll[p[x, n]]], {n, 3, 13}];
    a = Table[CoefficientList[FullSimplify[ExpandAll[p[x, n]]], x], {n, 3, 13}];
    Flatten[a]

Formula

p(x,n)=(If[n == 0, 1, x^n + 1 + x*D[( x + 1)^(n + 1), {x, 3}]]
- 2^n*(1 - x)^(1 + n)*LerchPhi[x, -n, 1/2])/x;
t(n,m)=coefficients(p(x,n))

A155865 Triangle T(n,k) = (n-1)*binomial(n-2, k-1) for 1 <= k <= n-1, n >= 2, and T(n,0) = T(n,n) = 1 for n >= 0, read by rows.

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 1, 2, 2, 1, 1, 3, 6, 3, 1, 1, 4, 12, 12, 4, 1, 1, 5, 20, 30, 20, 5, 1, 1, 6, 30, 60, 60, 30, 6, 1, 1, 7, 42, 105, 140, 105, 42, 7, 1, 1, 8, 56, 168, 280, 280, 168, 56, 8, 1, 1, 9, 72, 252, 504, 630, 504, 252, 72, 9, 1, 1, 10, 90, 360, 840, 1260, 1260, 840, 360, 90, 10, 1
Offset: 0

Views

Author

Roger L. Bagula, Jan 29 2009

Keywords

Examples

			Triangle begins:
  1;
  1, 1;
  1, 1,  1;
  1, 2,  2,   1;
  1, 3,  6,   3,   1;
  1, 4, 12,  12,   4,   1;
  1, 5, 20,  30,  20,   5,   1;
  1, 6, 30,  60,  60,  30,   6,   1;
  1, 7, 42, 105, 140, 105,  42,   7,  1;
  1, 8, 56, 168, 280, 280, 168,  56,  8, 1;
  1, 9, 72, 252, 504, 630, 504, 252, 72, 9, 1;
  ...
ConvOffs transform of (1, 1, 2, 3) = integers of row 4: (1, 3, 6, 3, 1). _Gary W. Adamson_, Jul 09 2012
		

Crossrefs

Cf. A002457 (T(2*n, n)), A155863, A155864.

Programs

  • Magma
    A155865:= func< n,k | k eq 0 or k eq n select 1 else (n-1)*Binomial(n-2, k-1) >;
    [A155865(n,k): k in [0..n], n in [0..12]]; // G. C. Greubel, Jun 04 2021
    
  • Mathematica
    p[x_, n_] = If[n==0, 1, 1 + x^n + x*D[(x+1)^(n-1), {x, 1}]];
    Flatten[Table[CoefficientList[ExpandAll[p[x, n]], x], {n, 0, 10}]]
    (* or *)
    q = 1;
    c[n_, q_]= If[n<2, 1, Product[(i-1)^q, {i, 2, n}]];
    T[n_, m_, q_]= c[n, q]/(c[m, q]*c[n-m, q]);
    Flatten[Table[T[n, m, q], {n,0,12}, {m, 0, n}]] (* Roger L. Bagula, Mar 09 2010 *)
  • Maxima
    T(n, k) := if k = 0 or k = n then 1 else (n-1)*binomial(n-2, k-1)$ create_list(T(n, k), n, 0, 12, k, 0, n); /* Franck Maminirina Ramaharo, Dec 05 2018 */
    
  • Sage
    def A155865(n,k): return 1 if (k==0 or k==n) else (n-1)*binomial(n-2, k-1)
    flatten([[A155865(n,k) for k in (0..n)] for n in (0..12)]) # G. C. Greubel, Jun 04 2021

Formula

T(n, k) = coefficients of (p(n, x)), where p(n, x) = 1 + x^n + x*((d/dx) (x+1)^n) and T(0, 0) = 1.
Define c(n) = Product_{i=2..n} (i - 1), with c(0) = c(1) = 1. Then T(n,m) = c(n)/(c(m)*c(n-m)). - Roger L. Bagula, Mar 09 2010
The triangle is the ConvOffsStoT transform of the natural numbers prefaced with a 1. A row with n integers is the ConvOffs transform of a finite series of the first (n-1) terms in (1, 1, 2, 3, 4, ...). See A214281 for definitions of the transform. - Gary W. Adamson, Jul 09 2012
Sum_{k=0..n} T(n, k) = 2 + A001787(n-1) - (3/4)*[n==0]. - R. J. Mathar, Jul 17 2012
From Franck Maminirina Ramaharo, Dec 05 2018: (Start)
T(n, k) = (n-1)*binomial(n-2, k-1) with T(n, 0) = T(n, n) = 1.
n-th row polynomial is (1/2)*(1 + (-1)^(2^n) + 2*x^n + (1 + (-1)^(2^n))*(n - 1)*x*(x + 1)^(n - 2)).
G.f.: 1/(1 - y) + 1/(1 - x*y) + x*y^2/(1 - (1 + x)*y)^2 - 1.
E.g.f.: exp(y) + exp(x*y) + x*(1 - (1 - (1 + x)*y)*exp((1 + x)*y))/(1 + x)^2 - 1. (End)
T(2*n, n) = A002457(n). - Alois P. Heinz, Dec 05 2018

Extensions

Edited and name clarified by Franck Maminirina Ramaharo, Dec 04 2018

A155864 Triangle T(n,k) = n*(n-1)*binomial(n-2, k-1) for 1 <= k <= n-1, n >= 2, and T(n,0) = T(n,n) = 1 for n >= 0, read by rows.

Original entry on oeis.org

1, 1, 1, 1, 2, 1, 1, 6, 6, 1, 1, 12, 24, 12, 1, 1, 20, 60, 60, 20, 1, 1, 30, 120, 180, 120, 30, 1, 1, 42, 210, 420, 420, 210, 42, 1, 1, 56, 336, 840, 1120, 840, 336, 56, 1, 1, 72, 504, 1512, 2520, 2520, 1512, 504, 72, 1, 1, 90, 720, 2520, 5040, 6300, 5040, 2520, 720, 90, 1
Offset: 0

Views

Author

Roger L. Bagula, Jan 29 2009

Keywords

Examples

			Triangle begins:
  1;
  1,  1;
  1,  2,   1;
  1,  6,   6,    1;
  1, 12,  24,   12,    1;
  1, 20,  60,   60,   20,    1;
  1, 30, 120,  180,  120,   30,    1;
  1, 42, 210,  420,  420,  210,   42,    1;
  1, 56, 336,  840, 1120,  840,  336,   56,   1;
  1, 72, 504, 1512, 2520, 2520, 1512,  504,  72,  1;
  1, 90, 720, 2520, 5040, 6300, 5040, 2520, 720, 90, 1;
  ...
		

Crossrefs

Programs

  • Magma
    A155864:= func< n,k | k eq 0 or k eq n select 1 else n*(n-1)*Binomial(n-2, k-1) >;
    [A155864(n,k): k in [0..n], n in [0..12]]; // G. C. Greubel, Jun 04 2021
    
  • Mathematica
    (* First program *)
    p[n_, x_]:= p[n,x]= If[n==0, 1, 1 + x^n + x*D[(x+1)^(n), {x, 2}]];
    Flatten[Table[CoefficientList[p[n,x], x], {n, 0, 12}]]
    (* Second program *)
    Table[If[k==0 || k==n, 1, 2*Binomial[n, 2]*Binomial[n-2, k-1]], {n,0,12}, {k,0,n}] //Flatten (* G. C. Greubel, Jun 04 2021 *)
  • Maxima
    T(n, k) := ratcoef(x^n + n*(n-1)*x*(x+1)^(n-2) + (1 + (-1)^(2^n))/2, x, k)$ create_list(T(n, k), n, 0, 12, k, 0, n); /* Franck Maminirina Ramaharo, Dec 04 2018 */
    
  • Sage
    def A155864(n,k): return 1 if (k==0 or k==n) else n*(n-1)*binomial(n-2,k-1)
    flatten([[A155864(n,k) for k in (0..n)] for n in (0..12)]) # G. C. Greubel, Jun 04 2021

Formula

T(n, k) = coefficients of p(n, x), where p(n, x) = 1 + x^n + x*((d/dx)^2 (1+x)^n), with T(0, 0) = 1.
From Franck Maminirina Ramaharo, Dec 04 2018: (Start)
T(n, k) = n*(n-1)*binomial(n-2, k-1) with T(n, 0) = T(n, n) = 1.
n-th row polynomial is x^n + n*(n - 1)*x*(x + 1)^(n - 2) + (1 + (-1)^(2^n))/2.
G.f.: 1/(1 - y) + 1/(1 - x*y) + 2*x*y^2/(1 - y - x*y)^3 - 1.
E.g.f.: exp(y) + exp(x*y) + x*y^2*exp(y + x*y) - 1. (End)
Sum_{k=0..n} T(n, k) = 2 - [n=0] + A001815(n). - G. C. Greubel, Jun 04 2021

Extensions

Edited and name clarified by Franck Maminirina Ramaharo, Dec 04 2018

A168621 Triangle read by rows: T(n,0) = T(n,n) = 1 for n >= 0, T(n,k) = ((n - 1)! + 1)*binomial(n, k) for 1 <= k <= n - 1, n >= 2.

Original entry on oeis.org

1, 1, 1, 1, 4, 1, 1, 9, 9, 1, 1, 28, 42, 28, 1, 1, 125, 250, 250, 125, 1, 1, 726, 1815, 2420, 1815, 726, 1, 1, 5047, 15141, 25235, 25235, 15141, 5047, 1, 1, 40328, 141148, 282296, 352870, 282296, 141148, 40328, 1, 1, 362889, 1451556, 3386964, 5080446, 5080446, 3386964, 1451556, 362889, 1
Offset: 0

Views

Author

Roger L. Bagula and Gary W. Adamson, Dec 01 2009

Keywords

Comments

Row 0 is 1, and row n gives the coefficients in the expansion of (x + 1)^n + (n - 1)!*((x + 1)^n - x^n -1). - Franck Maminirina Ramaharo, Dec 22 2018

Examples

			Triangle begins:
  1;
  1,     1;
  1,     4,      1;
  1,     9,      9,      1;
  1,    28,     42,     28,      1;
  1,   125,    250,    250,    125,      1;
  1,   726,   1815,   2420,   1815,    726,      1;
  1,  5047,  15141,  25235,  25235,  15141,   5047,     1;
  1, 40328, 141148, 282296, 352870, 282296, 141148, 40328, 1;
  ...
		

Crossrefs

Programs

  • Mathematica
    p[x_, n_] := If[n == 0, 1, (x + 1)^n + (n - 1)!*((x + 1)^n - x^n - 1)];
    Table[CoefficientList[p[x, n], x], {n, 0, 12}] // Flatten (* Franck Maminirina Ramaharo, Dec 22 2018 *)
  • Maxima
    T(n, k) := if k = 0 or k = n then 1 else ((n - 1)! + 1)*binomial(n, k)$
    create_list(T(n, k), n, 0, 12, k, 0, n); /* Franck Maminirina Ramaharo, Dec 22 2018 */

Formula

From Franck Maminirina Ramaharo, Dec 22 2018: (Start)
T(n,k) = A007318(n,k) + A219570(n,k) for 1 <= k <= n - 1, n >= 2.
E.g.f.: exp((1 + x)*y) + log((1 - y)*(1 - x*y)/(1 - (1 + x)*y)). (End)

Extensions

Edited by Franck Maminirina Ramaharo, Dec 22 2018 (previous definition and examples were the same as A168620, but with different entries, as pointed out by R. J. Mathar, Oct 21 2012)
Showing 1-4 of 4 results.