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A131875 A000012 * A131844. 2
1, 5, 4, 12, 5, 7, 22, 6, 8, 10, 35, 7, 9, 11, 13, 51, 8, 10, 12, 14, 16, 70, 9, 11, 13, 15, 17, 19, 92, 10, 12, 14, 16, 18, 20, 22, 117, 11, 13, 15, 17, 19, 21, 23, 25, 145, 12, 14, 16, 18, 20, 22, 24, 26, 28 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Left column = pentagonal numbers, A000326: (1, 5, 12, 22,...). Row sums = A001106: (1, 9, 24, 46, 75, 111,...).

LINKS

Table of n, a(n) for n=0..54.

FORMULA

A000012 * A131844 as infinite lower triangular matrices.

EXAMPLE

First few rows of the triangle are:

1;

5, 4;

12, 5, 7;

22, 6, 8, 10;

35, 7, 9, 11, 13;

51, 8, 10, 12, 14, 16;

70, 9, 11, 13, 15, 17, 19;

92, 10, 12, 14, 16, 18, 20, 22;

...

CROSSREFS

Cf. A131844, A001106, A000326.

Sequence in context: A262902 A215332 A298779 * A095871 A284551 A316671

Adjacent sequences:  A131872 A131873 A131874 * A131876 A131877 A131878

KEYWORD

nonn,tabl

AUTHOR

Gary W. Adamson, Jul 22 2007

STATUS

approved

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Last modified April 18 03:59 EDT 2021. Contains 343072 sequences. (Running on oeis4.)