A133091 A133080 * A002260.

1, 2, 2, 1, 2, 3, 2, 4, 6, 4, 1, 2, 3, 4, 5, 2, 4, 6, 8, 10, 6, 1, 2, 3, 4, 5, 6, 7, 2, 4, 6, 8, 10, 12, 14, 8, 1, 2, 3, 4, 5, 6, 7, 8, 9, 2, 4, 6, 8, 10, 12, 14, 16, 18, 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 2

Offset: 1

Author

Gary W. Adamson, Sep 09 2007

Keywords

• nonn
• tabl

Comments

Row sums = A133092: (1, 4, 6, 16, 15, 36, 28, ...).

Examples

			First few rows of the triangle:
  1;
  2,  2;
  1,  2,  3;
  2,  4,  6,  4;
  1,  2,  3,  4,  5;
  2,  4,  6,  8, 10,  6;
  1,  2,  3,  4,  5,  6,  7;
  ...
		

Links

• G. C. Greubel, Table of n, a(n) for the first 50 rows, flattened

Crossrefs

Cf. A133080, A002260, A133092.

Programs

Mathematica

T[n_, n_] := n; T[n_, k_] := (2 - (1 - (-1)^n)/2)*k; Table[T[n, k], {n, 1, 10}, {k, 1, n}] (* G. C. Greubel, Oct 21 2017 *)

PARI

for(n=1,10, for(k=1,n, print1(if(k==n, n,(2 - (1 - (-1)^n)/2)*k), ", "))) \\ G. C. Greubel, Oct 21 2017

Formula

A133080 * A002260 as infinite lower triangular matrices.

Odd n rows = (1,2,3,...,n). Even n rows = (2,4,6,...,n).

Extensions

Corrected and extended by Philippe Deléham, Mar 02 2012