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A160708 Convolution triangle by rows, row sums = the Robbins sequence, A005130 starting with offset 1. 4
1, 1, 1, 3, 1, 3, 18, 3, 3, 18, 192, 18, 9, 18, 192, 3472, 192, 54, 54, 192, 3472, 104964, 3472, 576, 324, 576, 3472, 104964, 5606272, 104964, 10416, 3456, 3456, 10416, 104964, 5306272 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,4

COMMENTS

Row sums = the Robbins sequence A005130, starting with offset 1: (1, 2, 7, 42, 429,...).

Right and left borders = A160707, the convolution square root of A005130.

LINKS

Table of n, a(n) for n=1..36.

FORMULA

Let M = an infinite lower triangular Toeplitz matrix with A160707 in every column: (1, 1, 3, 18, 192, 5472,...); where A160707 = the convolution square root of the Robbins sequence: (1, 2, 7, 42, 429, 7436,...). Let Q = an infinite lower triangular matrix with (1, 1, 3, 18, 192,...) as the main diagonal and the rest zeros. Triangle A160708 = M * Q.

EXAMPLE

First few rows of the triangle =

1;

1, 1;

3, 1, 3;

18, 3, 3, 18;

192, 18, 9, 18, 192;

3472, 192, 54, 54, 192, 3472;

104964, 3472, 576, 324, 576, 3472, 104964;

5606272, 104964, 10416, 3456, 3456, 10416, 104964, 5306272;

...

Example: row 5 = (192, 18, 9, 18, 192) = (192, 18, 3, 1, 1) * (1, 1, 3, 18, 192); where A005130(5) = 429 = (192 + 18 + 9 + 18 + 192).

CROSSREFS

Cf. A005130, A160707

Sequence in context: A112811 A197272 A276639 * A040173 A320952 A128777

Adjacent sequences:  A160705 A160706 A160707 * A160709 A160710 A160711

KEYWORD

nonn,tabl

AUTHOR

Gary W. Adamson, May 24 2009

STATUS

approved

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Last modified November 21 11:01 EST 2018. Contains 317447 sequences. (Running on oeis4.)