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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
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 (list; table; graph; refs; listen; history; text; internal format)
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 are:

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

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Last modified December 12 20:12 EST 2019. Contains 329961 sequences. (Running on oeis4.)