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 1-2 of 2 results.

A127625 Triangle T(n,k) = binomial(n-1,k-1)*A001511(k), 1<=k<=n, read by rows.

Original entry on oeis.org

1, 1, 2, 1, 4, 1, 1, 6, 3, 3, 1, 8, 6, 12, 1, 1, 10, 10, 30, 5, 2, 1, 12, 15, 60, 15, 12, 1, 1, 14, 21, 105, 35, 42, 7, 4, 1, 16, 28, 168, 70, 112, 28, 32, 1, 1, 18, 36, 252, 126, 252, 84, 144, 9, 2, 1, 20, 45, 360, 210, 504, 210, 480, 45, 20, 1
Offset: 1

Views

Author

Gary W. Adamson, Jan 20 2007

Keywords

Comments

Column k of Pascal's triangle is multiplied by the k-th entry of the ruler sequence.

Examples

			First few rows of the triangle are:
1;
1, 2;
1, 4, 1;
1, 6, 3, 3;
1, 8, 6, 12, 1;
1, 10, 10, 30, 5, 2;
1, 12, 15, 60, 15, 12, 1;
...
		

Crossrefs

Cf. A106461 (row sums), A001511.

Programs

  • Mathematica
    T[n_,k_]:=Binomial[n-1,k-1]*IntegerExponent[2k,2];Table[T[n,k],{n,9},{k,n}]//Flatten (* James C. McMahon, Jan 01 2025 *)

Formula

T(n,n) = A001511(n).

Extensions

a(46)-a(66) from James C. McMahon, Jan 01 2025

A129262 Triangle read by rows, A007318 * A115361.

Original entry on oeis.org

1, 2, 1, 3, 2, 1, 5, 4, 3, 1, 9, 8, 6, 4, 1, 16, 15, 11, 10, 5, 1, 27, 26, 21, 20, 15, 6, 1, 44, 43, 42, 36, 35, 21, 7, 1, 73, 72, 84, 64, 70, 56, 28, 8, 1, 130, 129, 162, 120, 127, 126, 84, 36, 9, 1, 251, 250, 297, 240, 220, 252, 210, 120, 45, 10, 1, 507, 506, 518, 495, 385, 463, 462, 330, 165, 55, 11, 1
Offset: 1

Views

Author

Gary W. Adamson, Apr 06 2007

Keywords

Comments

Row sums give A106461.
Left column is A119968.

Examples

			First few rows of the triangle:
  1;
  2,  1;
  3,  2,  1;
  5,  4,  3,  1;
  9,  8,  6,  4,  1;
 16, 15, 11, 10,  5,  1;
 27, 26, 21, 20, 15,  6,  1;
 44, 43, 42, 36, 35, 21,  7,  1;
  ...
		

Crossrefs

Formula

Binomial transform of A115361.

Extensions

Terms a(23) and following corrected by Georg Fischer, Jul 04 2023
Showing 1-2 of 2 results.