

A091014


Smallest number having exactly n divisors d such that for some x also dx and d+x are divisors.


1



1, 6, 18, 12, 30, 24, 36, 48, 132, 84, 72, 60, 312, 264, 816, 144, 270, 168, 252, 300, 288, 120, 810, 432, 1224, 180, 1188, 1140, 792, 630, 1152, 240, 2112, 672, 4104, 504, 420, 600, 3672, 540, 1872, 480, 2592, 1584, 900, 5100, 360, 2760, 2040, 1890
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

0,2


COMMENTS

A091009(a(n))=n and A091009(m)<>n for m<=a(n).


LINKS

Table of n, a(n) for n=0..49.


EXAMPLE

a(9)=84: the exactly 9 triples of divisors of 84 with the defining property: (1,2,3), (2,3,4), (2,4,6), (1,4,7), (2,7,12), (3,12,21), (7,14,21), (14,21,28) and (14,28,42).


CROSSREFS

Sequence in context: A129870 A331056 A274877 * A097370 A252897 A174904
Adjacent sequences: A091011 A091012 A091013 * A091015 A091016 A091017


KEYWORD

nonn


AUTHOR

Reinhard Zumkeller, Dec 13 2003


STATUS

approved



