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A143271 Triangle read by rows, A130209 * A000012 * A127648, 1<=k<=n. 1
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 (list; table; graph; refs; listen; history; text; internal format)
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

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Last modified November 17 16:00 EST 2019. Contains 329236 sequences. (Running on oeis4.)