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A127444 Triangle defined as the matrix product A051731*A127442, read by rows. 0
1, 2, -2, 2, -2, 0, 3, -4, 0, 1, 2, -2, 0, 1, -1, 4, -6, 0, 1, -1, 2, 2, -2, 0, 1, -1, 2, -2, 4, -6, 0, 2, -1, 2, -2, 1, 3, -4, 0, 1, -1, 2, -2, 1, 0, 4, -6, 0, 2, -2, 2, -2, 1, 0, 1, 2, -2, 0, 1, -1, 2, -2, 1, 0, 1, -2, 6, -10, 0, 3, -2, 4, -2, 1 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Row sums = 0.

LINKS

Table of n, a(n) for n=1..74.

FORMULA

T(n,k) = sum_{j=k..n} A051731(n,j)*A127442(j,k) = sum_{j=k..n, j|n} A127442(j,k), 1<=k<=n.

EXAMPLE

First few rows of the triangle are:

1;

2, -2;

2, -2, 0;

3, -4, 0, 1;

2, -2, 0, 1, -1;

4, -6, 0, 1, -1, 2;

2, -2, 0, 1, -1, 2, -2;

...

CROSSREFS

Cf. A000005 (column k=1), A051731, A127442.

Sequence in context: A214666 A320471 A333180 * A241477 A268243 A159782

Adjacent sequences:  A127441 A127442 A127443 * A127445 A127446 A127447

KEYWORD

tabl,easy,sign

AUTHOR

Gary W. Adamson, Jan 14 2007

STATUS

approved

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Last modified May 13 23:41 EDT 2021. Contains 343868 sequences. (Running on oeis4.)