A177991 Triangle read by rows, A070909 * A177990.

1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 2, 1, 1, 1, 1, 3, 1, 2, 1, 1, 1, 3, 1, 2, 1, 1, 1, 1, 4, 1, 3, 1, 2, 1, 1, 1, 4, 1, 3, 1, 2, 1, 1, 1, 1, 5, 1, 4, 1, 3, 1, 2, 1, 1, 1, 5, 1, 4, 1, 3, 1, 2, 1, 1, 1

Offset: 0

Author

Gary W. Adamson, May 16 2010

Keywords

• nonn
• tabl

Comments

Row sums = A117142: (1, 2, 3, 5, 6, 9,...)

Examples

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

Links

• Peter Bala, Matrices with repeated columns - the generalised Appell groups

Crossrefs

A177994 = A177990 * A070909.

Cf. A117142.

Formula

As infinite lower triangular matrices, A070909 * A177990

Extensions

a(28)=1 inserted before the first "4" by Georg Fischer, Dec 28 2021