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

0,8

Comments

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

Links

Table of n, a(n) for n=0..65.

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

Formula

As infinite lower triangular matrices, A070909 * A177990

Example

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;
...

Crossrefs

A177994 = A177990 * A070909.

Cf. A117142.

Sequence in context: A238747 A101873 A336691 * A146289 A214575 A081418

Adjacent sequences: A177988 A177989 A177990 * A177992 A177993 A177994

Keyword

nonn,tabl

Author

Gary W. Adamson, May 16 2010

Extensions

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

Status

approved