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 1-3 of 3 results.

A168620 Table T(n,k) with the coefficient [x^k] of the polynomial 5*(x+1)^n - 4*(x^n+1) in column 0<=k<=n. T(0,0)=1.

Original entry on oeis.org

1, 1, 1, 1, 10, 1, 1, 15, 15, 1, 1, 20, 30, 20, 1, 1, 25, 50, 50, 25, 1, 1, 30, 75, 100, 75, 30, 1, 1, 35, 105, 175, 175, 105, 35, 1, 1, 40, 140, 280, 350, 280, 140, 40, 1, 1, 45, 180, 420, 630, 630, 420, 180, 45, 1, 1, 50, 225, 600, 1050, 1260, 1050, 600, 225, 50, 1
Offset: 0

Views

Author

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

Keywords

Comments

Row sums are apparently in A154252.

Examples

			1;
1, 1;
1, 10, 1;
1, 15, 15, 1;
1, 20, 30, 20, 1;
1, 25, 50, 50, 25, 1;
1, 30, 75, 100, 75, 30, 1;
1, 35, 105, 175, 175, 105, 35, 1;
1, 40, 140, 280, 350, 280, 140, 40, 1;
1, 45, 180, 420, 630, 630, 420, 180, 45, 1;
1, 50, 225, 600, 1050, 1260, 1050, 600, 225, 50, 1;
		

Programs

  • Mathematica
    m = 2; p[x_, n_] := If[n == 0, 1, (2*m + 1)(x + 1)^n - 2*m*(x^n + 1)]
    a = Table[CoefficientList[p[x, n], x], {n, 0, 10}];
    Flatten[a]

A154312 Triangle T(n,k), 0<=k<=n, read by rows, given by [0,1/2,-1/2,0,0,0,0,0,0,0,...] DELTA [2,-1/2,-1/2,2,0,0,0,0,0,0,0 ...] where DELTA is the operator defined in A084938 .

Original entry on oeis.org

1, 0, 2, 0, 1, 3, 0, 0, 3, 5, 0, 0, 0, 7, 9, 0, 0, 0, 0, 15, 17, 0, 0, 0, 0, 0, 31, 33, 0, 0, 0, 0, 0, 0, 63, 65, 0, 0, 0, 0, 0, 0, 0, 127, 129, 0, 0, 0, 0, 0, 0, 0, 0, 255, 257, 0, 0, 0, 0, 0, 0, 0, 0, 0, 511, 513, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1023, 1025, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2047
Offset: 0

Views

Author

Philippe Deléham, Jan 07 2009

Keywords

Comments

Column sums give A003945.

Examples

			Triangle begins:
1;
0, 2;
0, 1, 3;
0, 0, 3, 5;
0, 0, 0, 7, 9;
0, 0, 0, 0, 15, 17; ...
		

Crossrefs

Formula

Sum_{k, 0<=k<=n}T(n,k)*x^(n-k)= A040000(n), A094373(n), A000079(n), A083329(n), A095121(n), A154117(n), A131128(n), A154118(n), A131130(n), A154251(n), A154252(n) for x = -1,0,1,2,3,4,5,6,7,8,9 respectively.
G.f.: (1-x*y+x^2*y-x^2*y^2)/(1-3*x*y+2*x^2*y^2). - Philippe Deléham, Nov 02 2013
T(n,k) = 3*T(n-1,k-1) - 2*T(n-2,k-2), T(0,0) = 1, T(1,0) = 0, T(1,1) = 2, T(2,0) = 0, T(2,1) = 1, T(2,2) = 3, T(n,k) = 0 if k<0 or if k>n. - Philippe Deléham, Nov 02 2013

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 1-3 of 3 results.