A104571 Triangle T(n,k) = A042948(n-k+1) read by rows, 0<=k<=n.

1, 4, 1, 5, 4, 1, 8, 5, 4, 1, 9, 8, 5, 4, 1, 12, 9, 8, 5, 4, 1, 13, 12, 9, 8, 5, 4, 1, 16, 13, 12, 9, 8, 5, 4, 1

Offset

0,2

Links

Table of n, a(n) for n=0..35.

Formula

The triangle is extracted from the product of lower triangular matrices (with the rest of the terms all zeros): G * R (or R * G); G = [1; 3, 1; 1, 3, 1; 3, 1, 3, 1;...]; R = [1; 1, 1; 1, 1, 1;...].

Example

The first few rows are:
1;
4, 1;
5, 4, 1;
8, 5, 4, 1;
9, 8, 5, 4, 1;
...

Crossrefs

Cf. A042948, A035608 (row sums), A104570, A104569, A074377.

Sequence in context: A214892 A030352 A212643 * A249057 A105721 A099310

Adjacent sequences: A104568 A104569 A104570 * A104572 A104573 A104574

Keyword

nonn,tabl,easy

Author

Gary W. Adamson, Mar 16 2005

Status

approved