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A143355 Triangle read by rows, A051731 * A010766, 1<=k<=n. 1
1, 3, 1, 4, 1, 1, 7, 3, 1, 1, 6, 2, 1, 1, 1, 12, 5, 3, 1, 1, 1, 8, 3, 2, 1, 1, 1, 1, 15, 7, 3, 3, 1, 1, 1, 1, 13, 5, 4, 2, 1, 1, 1, 1, 1, 18, 8, 4, 3, 3, 1, 1, 1, 1, 1, 12, 5, 3, 2, 2, 1, 1, 1, 1, 1, 1, 28, 13, 8, 5, 3, 31, 1, 1, 1, 1, 1 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Left column = sigma(n), A000203.

Row sums = A143356: (1, 4, 56, 12, 11, 23, 17,...).

LINKS

Table of n, a(n) for n=1..77.

FORMULA

Triangle read by rows, A051731 * A010766, 1<=k<=n

EXAMPLE

First few rows of the triangle =

1;

3, 1;

4, 1, 1;

7, 3, 1, 1;

6, 2, 1, 1, 1;

12, 5, 3, 1, 1, 1;

8, 3, 2, 1, 1, 1, 1;

15, 7, 3, 3, 1, 1, 1, 1;

...

CROSSREFS

Cf. A051731, A010766, A000203, A143356.

Sequence in context: A130314 A334466 A127057 * A143319 A078011 A010285

Adjacent sequences:  A143352 A143353 A143354 * A143356 A143357 A143358

KEYWORD

nonn,tabl

AUTHOR

Gary W. Adamson, Aug 10 2008

STATUS

approved

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Last modified May 6 01:03 EDT 2021. Contains 343579 sequences. (Running on oeis4.)