

A117427


Triangle T, read by rows, equal to the matrix square of triangle A117418; also equals a column bisection of triangle A117418: column 2k+1 of T^(1/2) equals column k of T.


3



1, 2, 1, 4, 4, 1, 9, 14, 6, 1, 23, 50, 28, 8, 1, 66, 191, 126, 48, 10, 1, 209, 780, 572, 264, 70, 12, 1, 724, 3415, 2692, 1440, 438, 98, 14, 1, 2722, 15924, 13203, 7990, 2646, 698, 130, 16, 1, 11054, 78595, 67542, 45566, 15920, 4702, 1029, 168, 18, 1, 48221, 408337
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OFFSET

0,2


LINKS

Table of n, a(n) for n=0..56.


EXAMPLE

Triangle T begins:
1;
2, 1;
4, 4, 1;
9, 14, 6, 1;
23, 50, 28, 8, 1;
66, 191, 126, 48, 10, 1;
209, 780, 572, 264, 70, 12, 1;
724, 3415, 2692, 1440, 438, 98, 14, 1;
2722, 15924, 13203, 7990, 2646, 698, 130, 16, 1;
11054, 78595, 67542, 45566, 15920, 4702, 1029, 168, 18, 1; ...
The matrix squareroot T^(1/2) = A117418, which begins:
1;
1, 1;
1, 2, 1;
1, 4, 3, 1;
1, 9, 8, 4, 1;
1, 23, 22, 14, 5, 1;
1, 66, 65, 50, 20, 6, 1;
1, 209, 208, 191, 79, 28, 7, 1; ...
where column 2k+1 of T^(1/2) equals column k of T for k>=0.


PROG

(PARI)


CROSSREFS

Cf. A117428 (row sums); A117418 (T^(1/2)), A117425 (dual).
Sequence in context: A263989 A202710 A200965 * A097761 A200756 A108556
Adjacent sequences: A117424 A117425 A117426 * A117428 A117429 A117430


KEYWORD

nonn,tabl


AUTHOR

Paul D. Hanna, Mar 14 2006


STATUS

approved



