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.

A125101 T(n,k) = k*binomial(n-1,k-1) + Fibonacci(k)*binomial(n-1,k) (1 <= k <= n).

Original entry on oeis.org

1, 2, 2, 3, 5, 3, 4, 9, 11, 4, 5, 14, 26, 19, 5, 6, 20, 50, 55, 30, 6, 7, 27, 85, 125, 105, 44, 7, 8, 35, 133, 245, 280, 182, 62, 8, 9, 44, 196, 434, 630, 560, 300, 85, 9, 10, 54, 276, 714, 1260, 1428, 1056, 477, 115, 10, 11, 65, 375, 1110, 2310, 3192, 3030, 1905, 745, 155
Offset: 1

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Author

Gary W. Adamson, Nov 20 2006

Keywords

Comments

Row sums are s(n) = 1, 4, 11, 28, 69, 167, 400, ...
Binomial transform of the bidiagonal matrix with (1,2,3...) in the main diagonal and the Fibonacci numbers (1,1,2,3,5,8,...) in the subdiagonal.

Examples

			First few rows of the triangle:
  1;
  2,  2;
  3,  5,   3;
  4,  9,  11,   4;
  5, 14,  26,  19,   5;
  6, 20,  50,  55,  30,   6;
  7, 27,  85, 125, 105,  44,  7;
  8, 35, 133, 245, 280, 182, 62, 8;
  ...
		

Crossrefs

Programs

  • Maple
    with(combinat): T:=(n,k)->k*binomial(n-1,k-1)+fibonacci(k)*binomial(n-1,k): for n from 1 to 12 do seq(T(n,k),k=1..n) od; # yields sequence in triangular form
  • Mathematica
    Flatten[Table[k Binomial[n-1,k-1]+Fibonacci[k]Binomial[n-1,k],{n,15},{k,n}]] (* Harvey P. Dale, Nov 03 2014 *)

Formula

T(n,2) = A000096(n-1).
T(n,3) = A051925(n-1).
T(n,4) = A215862(n-3). - R. J. Mathar, Aug 10 2013
Row sums s(n) = 7*s(n-1) -17*s(n-2) +16*s(n-3) -4*s(n-4) with s(n) = A001787(n+1)/4 +A001906(n-1). - R. J. Mathar, Aug 10 2013

Extensions

Edited by N. J. A. Sloane, Nov 29 2006