



1, 2, 4, 3, 6, 6, 4, 8, 8, 12, 5, 10, 10, 15, 10, 6, 12, 12, 18, 12, 24, 7, 14, 14, 21, 14, 28, 14, 8, 16, 16, 24, 16, 32, 16, 32, 9, 18, 18, 27, 18, 36, 18, 36, 27, 10, 20, 30, 20, 40, 20, 40, 30, 40, 11, 22, 22, 33, 22, 44, 22, 44, 33, 44, 22
(list;
table;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,2


COMMENTS

Row sums = A143274: (1, 6, 15, 32, 50, 84,...).


LINKS

Table of n, a(n) for n=1..65.


FORMULA

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


EXAMPLE

First few rows of the triangle =
1;
2, 4;
3, 6, 6;
4, 8, 8, 12;
5, 10, 10, 15, 10;
6, 12, 12, 18, 12, 24;
7, 14, 14, 21, 14, 28, 14;
8, 16, 16, 24, 16, 32, 16, 32;
...
T(6,3) = 12 = 6*d(3) =6*2, where A000005 = d(k) = (1, 2, 3, 2, 2, 4, 2, 4, 3,...)


PROG

(PARI) tabl(nn) = for (n=1, nn, for (k=1, n, print1(n*numdiv(k), ", ")); print(); ); \\ Michel Marcus, Mar 19 2016


CROSSREFS

Cf. A000005, A127648, A130209, A143274.
Sequence in context: A091850 A332450 A245454 * A141429 A309131 A162953
Adjacent sequences: A143270 A143271 A143272 * A143274 A143275 A143276


KEYWORD

nonn,tabl


AUTHOR

Gary W. Adamson, Aug 03 2008


STATUS

approved



