A128219 A000012 * A127701. a(1) = 1, a(2) = 2, a(3) = 2; by rows, n-1 terms of 2, 3, 4, ... followed by "n".

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

Offset: 1

Author

Gary W. Adamson, Feb 19 2007

Keywords

• nonn
• tabl

Examples

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

Crossrefs

Cf. A000012, A127701, A034856 (row sums), A128220.

Programs

Mathematica

trm[i_]:=Join[Range[2,i],{i}]; Flatten[Table[trm[n],{n,13}]] (* Harvey P. Dale, Nov 14 2012 *)

Formula

A000012 * A127701 as infinite lower triangular matrices.