



1, 2, 4, 2, 4, 6, 3, 6, 9, 12, 2, 4, 6, 8, 10, 4, 8, 12, 16, 20, 24, 2, 4, 6, 8, 10, 12, 14, 4, 8, 12, 16, 20, 24, 28, 32, 3, 6, 9, 12, 15, 18, 21, 24, 27, 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 2, 4, 6, 8, 10, 12, 146, 16, 18, 20, 22, 6, 12, 18, 24, 30, 36, 42, 48, 54, 60, 66, 72
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OFFSET

1,2


COMMENTS

Row sums = A143272: (1, 6, 12, 30, 30, 84, 56,...).
Left border = A000005: (1, 2, 2, 3, 2, 4, 2, 4, 3,...).


LINKS

Table of n, a(n) for n=1..78.


FORMULA

Triangle read by rows, A130209 * A000012 * A127648, 1<=k<=n. T(n,k) = d(n)*k


EXAMPLE

First few rows of the triangle =
1;
2, 4;
2, 4, 6;
3, 6, 9, 12;
2, 4, 6, 8, 10;
4, 8, 12, 16, 20, 24;
2, 4, 6, 8, 10, 12, 14;
...
T(5,3) = 6 = 2*3 = d(5)*3


CROSSREFS

Cf. A000005, A143272, A130209, A127648.
Sequence in context: A214781 A214850 A236186 * A267654 A128859 A047975
Adjacent sequences: A143268 A143269 A143270 * A143272 A143273 A143274


KEYWORD

nonn,tabl


AUTHOR

Gary W. Adamson, Aug 03 2008


STATUS

approved



