OFFSET
1,2
COMMENTS
T(n,k) is the n-th positive integer with exactly k odd divisors.
This is a permutation of the natural numbers.
T(n,k) is also the n-th number j with the property that the symmetric representation of sigma(j) has k subparts (cf. A279387). - Omar E. Pol, Dec 27 2016
T(n,k) is also the n-th positive integer with exactly k partitions into consecutive parts. - Omar E. Pol, Aug 16 2018
LINKS
EXAMPLE
The corner of the square array begins:
1, 3, 9, 15, 81, 45, 729, 105, 225, 405, ...
2, 5, 18, 21, 162, 63, 1458, 135, 441, 567, ...
4, 6, 25, 27, 324, 75, 2916, 165, 450, 810, ...
8, 7, 36, 30, 625, 90, 5832, 189, 882, 891, ...
16, 10, 49, 33, 648, 99, 11664, 195, 900, 1053, ...
32, 11, 50, 35, 1250, 117, 15625, 210, 1089, 1134, ...
64, 12, 72, 39, 1296, 126, 23328, 231, 1225, 1377, ...
128, 13, 98, 42, 2401, 147, 31250, 255, 1521, 1539, ...
...
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Omar E. Pol, Apr 02 2016
STATUS
approved