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A156665 Triangle read by rows, A156663 * A007318 2
1, 1, 1, 3, 2, 1, 3, 5, 3, 1, 7, 8, 8, 4, 1, 7, 15, 16, 12, 5, 1, 15, 22, 31, 28, 17, 6, 1, 15, 37, 53, 59, 45, 23, 7, 1, 31, 52, 90, 112, 104, 68, 30, 8, 1, 31, 83, 142, 202, 216, 172, 98, 38, 9, 1, 63, 114, 225, 344, 418, 388, 270, 136, 47, 10, 1 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

0,4

COMMENTS

Row sums = A122746: (1, 2, 6, 12, 28, 56, 120,...).

LINKS

Robert Israel, Table of n, a(n) for n = 0..10010 (first 141 rows, flattened)

FORMULA

Triangle read by rows, A156663 * A007318

G.f. for triangle: 1/((1-2*x^2)*(1-x-x*y)). - Robert Israel, Aug 10 2015

EXAMPLE

First few rows of the triangle =

1;

1, 1;

3, 2, 1;

3, 5, 3, 1;

7, 8, 8, 4, 1;

7, 15, 16, 12, 5, 1;

15, 22, 31, 28, 17, 6, 1;

15, 37, 53, 59, 45, 23, 7, 1;

31, 52, 90, 112, 104, 68, 30, 8, 1;

31, 83, 142, 202, 216, 172, 98, 38, 9, 1;

63, 114, 225, 344, 418, 388, 270, 136, 47, 10, 1;

...

MAPLE

N:= 12: # for the first N rows

A156663:= Matrix(N, N, (i, j) -> `if`((i-j)::even, 2^((i-j)/2), 0), shape=triangular[lower]):

A007318:= Matrix(N, N, (i, j) -> binomial(i-1, j-1), shape=triangular[lower]):

P:= A156663 . A007318:

seq(seq(P[i, j], j=1..i), i=1..N); # Robert Israel, Aug 10 2015

CROSSREFS

A156663, A122746

Sequence in context: A318582 A318317 A129690 * A215415 A244477 A035572

Adjacent sequences:  A156662 A156663 A156664 * A156666 A156667 A156668

KEYWORD

nonn,tabl

AUTHOR

Gary W. Adamson, Feb 12 2009

STATUS

approved

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Last modified May 23 11:01 EDT 2019. Contains 323513 sequences. (Running on oeis4.)