

A266531


Square array read by antidiagonals upwards: T(n,k) = nth number with k odd divisors.


9



1, 2, 3, 4, 5, 9, 8, 6, 18, 15, 16, 7, 25, 21, 81, 32, 10, 36, 27, 162, 45, 64, 11, 49, 30, 324, 63, 729, 128, 12, 50, 33, 625, 75, 1458, 105, 256, 13, 72, 35, 648, 90, 2916, 135, 225, 512, 14, 98, 39, 1250, 99, 5832, 165, 441, 405, 1024, 17, 100, 42, 1296, 117, 11664, 189, 450, 567, 59049, 2048, 19, 121, 51, 2401, 126, 15625
(list;
table;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,2


COMMENTS

T(n,k) is the nth positive integer with exactly k odd divisors.
This is a permutation of the natural numbers.
T(n,k) is also the nth 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 nth positive integer with exactly k partitions into consecutive parts.  Omar E. Pol, Aug 16 2018


LINKS

Table of n, a(n) for n=1..73.
Index entries for sequences that are permutations of the natural numbers


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

Row 1 is A038547.
Column 110: A000079, A038550, A072502, apparently A131651, A267696, A230577, A267697, A267891, A267892, A267893.
Cf. A001227, A182469, A236104, A237591, A237593, A240062, A261697, A261698, A261699, A279387, A286000, A286001, A296508.
Sequence in context: A164340 A046021 A319023 * A284311 A174225 A182945
Adjacent sequences: A266528 A266529 A266530 * A266532 A266533 A266534


KEYWORD

nonn,tabl


AUTHOR

Omar E. Pol, Apr 02 2016


STATUS

approved



