OFFSET
1,3
COMMENTS
A two-dimensional arrangement of squares has the property that the number of vertices in row n equals the number of divisors of n. So T(n,k) is represented in the structure as the k-th vertex of row n (see the illustration of initial terms).
LINKS
Michel Marcus, Rows 1..1000, flattened
Omar E. Pol, Illustration of initial terms
EXAMPLE
Written as an irregular triangle the sequence begins:
1;
1, 2;
1, 3;
1, 4, 2;
1, 5;
1, 6, 2, 3;
1, 7;
1, 8, 2, 4;
1, 9, 3;
1, 10, 2, 5;
1, 11;
1, 12, 2, 6, 3, 4;
PROG
(PARI) row(n) = my(d=divisors(n)); vector(#d, k, if (k % 2, d[(k+1)/2], d[#d-k/2+1])); \\ Michel Marcus, Jun 20 2019
CROSSREFS
KEYWORD
nonn,tabf
AUTHOR
Omar E. Pol, Jul 29 2012
STATUS
approved