OFFSET
1,2
COMMENTS
If a(n) = q (say) is not zero, then x = q*d(x) has only a finite number of solutions. See A036763 for the numbers which cannot be expressible as m/d(m) for some m.
a(9p) = 0 for all primes p. - Jianing Song, Nov 25 2018
LINKS
Nathaniel Johnston, Table of n, a(n) for n = 1..1250
EXAMPLE
If q=25 then 25*9 = 225, 25*18 = 450 and 25*24 = 600 so that d(225), d(450), d(600) are 9, 18, 24, respectively. The smallest is 225. Thus a(25)=225.
MAPLE
with(numtheory): A036764 := proc(n) local k, p: for k from 1 to 4*n^2 do p:=n*k: if(p=n*tau(p))then return p: fi: od: return 0: end: seq(A036764(n), n=1..40); # Nathaniel Johnston, May 04 2011
CROSSREFS
KEYWORD
nonn
AUTHOR
EXTENSIONS
Additional comments from Asher Auel, May 17 2001
STATUS
approved