A127701 Infinite lower triangular matrix with (1, 2, 3, ...) in the main diagonal, (1, 1, 1, ...) in the subdiagonal and the rest zeros.

1, 1, 2, 0, 1, 3, 0, 0, 1, 4, 0, 0, 0, 1, 5, 0, 0, 0, 0, 1, 6, 0, 0, 0, 0, 0, 1, 7, 0, 0, 0, 0, 0, 0, 1, 8, 0, 0, 0, 0, 0, 0, 0, 1, 9, 0, 0, 0, 0, 0, 0, 0, 0, 1, 10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 11, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 12, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 13, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0

Offset: 1

Author

Gary W. Adamson, Jan 23 2007

Keywords

• nonn
• easy
• tabl

Comments

Eigensequence of the triangle = A001040 starting (1, 3, 10, 43, 225, ...). - Gary W. Adamson, Dec 29 2008

Examples

			First few rows of the triangle are:
  1;
  1, 2;
  0, 1, 3;
  0, 0, 1, 4;
  0, 0, 0, 1, 5;
  0, 0, 0, 0, 1, 6;
  0, 0, 0, 0, 0, 1, 7;
  ...
		

Crossrefs

Cf. A001040. - Gary W. Adamson, Dec 29 2008

Programs

Mathematica

Join[{1},Flatten[Table[Join[{PadRight[{},n-2,0],1,n}],{n,2,15}]]] (* Harvey P. Dale, Jan 06 2014 *)

Extensions

More terms from Jon E. Schoenfield, May 26 2007