A140168 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.

1, 2, 1, 4, 1, 1, 8, 3, 3, 1, 16, 5, 9, 2, 1, 32, 11, 23, 7, 4, 1, 64, 21, 57, 16, 15, 3, 1, 128, 43, 135, 41, 46, 12, 5, 1, 256, 85, 313, 94, 133, 34, 22, 4, 1, 512, 171, 711, 219, 360, 99, 78, 18, 6, 1, 1024, 341, 1593, 492, 939, 261, 255, 60, 30, 5, 1, 2048, 683, 3527, 1101

Offset

0,2

Comments

Row sums = A105476 starting (1, 3, 6, 15, 33, 78, 177, ...).

Links

Table of n, a(n) for n=0..69.

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:
    1;
    2,   1;
    4,   1,   1;
    8,   3,   3,   1;
   16,   5,   9,   2,   1;
   32,  11,  23,   7,   4,  1;
   64,  21,  57,  16,  15,  3,  1;
  128,  43, 135,  41,  46, 12,  5,  1;
  256,  85, 313,  94, 133, 34, 22,  4, 1;
  512, 171, 711, 219, 360, 99, 78, 18, 6, 1;
  ...

Crossrefs

Cf. A105476.

Sequence in context: A117352 A137710 A068009 * A059119 A305333 A127772

Adjacent sequences: A140165 A140166 A140167 * A140169 A140170 A140171

Keyword

nonn,tabl

Author

Gary W. Adamson, May 10 2008

Status

approved