A140169 Triangle read by rows, iterates of X * [1,0,0,0,...] where X = an infinite bidiagonal matrix with (2,1,2,1,2,1,...) in the main diagonal, (1,2,1,2,1,2,...) in the subdiagonal and the rest zeros.

1, 2, 1, 4, 3, 2, 8, 7, 10, 2, 16, 15, 34, 12, 4, 32, 31, 98, 46, 32, 4, 64, 63, 258, 144, 156, 36, 8, 128, 127, 642, 402, 600, 192, 88, 8, 256, 255, 1358, 1044, 2004, 792, 560, 96, 16, 512, 511, 3586, 2582, 6096, 2796, 2704, 656, 224, 16, 1024, 1023, 8194, 6168, 17356

Offset

0,2

Comments

Row sums = 3^n: (1, 3, 9, 27, 81,...)

Links

Table of n, a(n) for n=0..59.

Formula

Triangle read by rows, iterates of X * [1,0,0,0,...]; where X = an infinite bidiagonal matrix with [2, -1, 2, -1, 2,...] in the main diagonal, [1, 1, 1,...] in the subdiagonal and rest zeros.

Example

First few rows of the triangle are:
1;
2, 1;
4, 3, 2;
8, 7, 10, 2;
16, 15, 34, 12, 4;
32, 31, 98, 46, 32, 4;
64, 63, 258, 144, 156, 36, 8;
128, 126, 642, 402, 600, 192, 88, 8;
...

Crossrefs

Sequence in context: A182013 A144333 A126136 * A124731 A210658 A376572

Adjacent sequences: A140166 A140167 A140168 * A140170 A140171 A140172

Keyword

nonn,tabl

Author

Gary W. Adamson, May 10 2008

Status

approved