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A143218 Triangle read by rows, A127775 * A000012 * A127775; 1<=k<=n. 0
1, 3, 9, 5, 15, 25, 7, 21, 35, 49, 9, 27, 45, 63, 81, 11, 33, 55, 77, 99, 121, 13, 39, 65, 91, 117, 143, 169, 15, 45, 75, 105, 135, 165, 195, 225, 17, 51, 85, 119, 153, 187, 221, 255, 289, 19, 57, 95, 133, 171, 209, 247, 285, 323, 361, 21, 63, 105, 147, 189, 231, 273, 315 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Row sums = A015237: (1, 12, 45, 112, 225, 396,...)

LINKS

Table of n, a(n) for n=1..63.

FORMULA

Triangle read by rows, A127775 * A000012 * A127775. T(n,k) = (2*n - 1) * (2*k - 1), 1<=k<=n.

EXAMPLE

First few rows of the triangle =

1;

3, 9;

5, 15, 25;

7, 21, 35, 49;

9, 27, 45, 63, 81;

11, 33, 55, 77, 99, 121;

13, 39, 65, 91, 117, 143, 169;

...

T(5,3) = 45 = 9*5 = (2*5 - 1) * (2*3 - 1).

CROSSREFS

Cf. A005408, A127775, A015237.

Sequence in context: A134001 A338350 A088898 * A262024 A252117 A103934

Adjacent sequences:  A143215 A143216 A143217 * A143219 A143220 A143221

KEYWORD

nonn,tabl

AUTHOR

Gary W. Adamson, Jul 30 2008

STATUS

approved

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Last modified May 10 00:35 EDT 2021. Contains 343747 sequences. (Running on oeis4.)