



1, 2, 1, 4, 2, 1, 4, 4, 2, 1, 6, 4, 4, 2, 1, 6, 6, 4, 4, 2, 1, 8, 6, 6, 4, 4, 2, 1, 8, 8, 6, 6, 4, 4, 2, 1, 10, 8, 8, 6, 6, 4, 4, 2, 1, 10, 10, 8, 8, 6, 6, 4, 4, 2, 1
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OFFSET

1,2


COMMENTS

Row sums = A047838: (1, 3, 7, 11, 17, 23, 31, 39,...). The triangle is a companion to A135151.


LINKS

Table of n, a(n) for n=1..55.


FORMULA

A004736 + A128174  I, where I = Identity matrix, A004736 = (1; 2,1; 3,2,1;...) and A128174 = (1; 0,1; 1,0,1; 0,1,0,1;...).


EXAMPLE

First few rows of the triangle are:
1;
2, 1;
4, 2, 1;
4, 4, 2, 1;
6, 4, 4, 2, 1;
6, 6, 4, 4, 2, 1;
8, 6, 6, 4, 4, 2, 1;
...


CROSSREFS

Cf. A135151, A047838, A004736, A128174.
Sequence in context: A243060 A118235 A083653 * A147542 A211956 A128177
Adjacent sequences: A135149 A135150 A135151 * A135153 A135154 A135155


KEYWORD

nonn,tabl


AUTHOR

Gary W. Adamson, Nov 21 2007


STATUS

approved



