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A127574 Triangle T(n,k) = k*sigma(n) if k divides n, else 0. 1
1, 3, 6, 4, 0, 12, 7, 14, 0, 28, 6, 0, 0, 0, 30, 12, 24, 36, 0, 0, 72, 8, 0, 0, 0, 0, 0, 56, 15, 30, 0, 60, 0, 0, 0, 120, 13, 0, 39, 0, 0, 0, 0, 0, 117, 18, 36, 0, 0, 90, 0, 0, 0, 0, 180, 12, 0, 0, 0, 0, 0, 0, 0, 0, 0, 132, 28, 56, 84, 112, 0, 168, 0, 0, 0, 0, 0, 336 (list; table; graph; refs; listen; history; text; internal format)
OFFSET
1,2
LINKS
FORMULA
T(n,k) = Sum_{j=k..n} A130208(n,j)*A127093(j,k), product of the two infinite lower triangular matrices.
T(n,1) = A000203(n).
T(n,n) = A064987(n).
EXAMPLE
First few rows of the triangle are:
1;
3, 6;
4, 0, 12;
7, 14, 0, 28;
6, 0, 0, 0, 30;
12, 24, 36, 0, 0, 72;
...
CROSSREFS
Cf. A127093, A127573, A064987, A000203, A072861 (row sums).
Sequence in context: A265480 A309084 A288092 * A356501 A334279 A334278
KEYWORD
nonn,tabl
AUTHOR
Gary W. Adamson, Jan 19 2007
STATUS
approved

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Last modified March 19 01:22 EDT 2024. Contains 370952 sequences. (Running on oeis4.)