OFFSET
1,2
COMMENTS
EXAMPLE
Written as an irregular triangle the sequence begins:
1;
3;
1, 3;
3, 4;
1, 5;
6, 6;
1, 7;
3, 4, 8;
1, 3, 9;
3, 5, 10;
1, 11;
10, 6, 12;
1, 13;
3, 7, 14;
1, 3, 5, 15;
3, 4, 8, 16;
1, 17;
6, 6, 9, 18;
1, 19;
3, 9, 10, 20;
...
For n = 20 and k = 2 the divisors of 20 are [1, 2, 4, 5, 10, 20], there are four divisor islands: [1, 2], [4, 5], [10], [20] and the sum of the second divisor island is 4 + 5 = 9, so T(20,2) = 9.
CROSSREFS
KEYWORD
nonn,tabf
AUTHOR
Omar E. Pol, Jul 24 2014
STATUS
approved