OFFSET
1,2
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
EXAMPLE
The positive divisors of 12 are 1,2,3,4,6,12. Checking the partial products: 1=1, 1*2=2, 1*2*3=6, 1*2*3*4=24, 1*2*3*4*6 = 144, 1*2*3*4*6*12 = 1728. 24 is the smallest such product which is >= 12. So a(12) = 24.
MAPLE
with(numtheory): a:=proc(n) local div, j, pr: div:=divisors(n): for j while product(div[i], i=1..j)< n do pr:=product(div[i], i=1..j+1) end do: pr end proc: 1, seq(a(n), n=2..60); # Emeric Deutsch, Dec 18 2007
MATHEMATICA
Table[SelectFirst[FoldList[Times, Divisors[n]], #>=n&], {n, 60}] (* The program uses the SelectFirst function from Mathematica version 10 *) (* Harvey P. Dale, Sep 06 2015 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Leroy Quet, Dec 03 2007
EXTENSIONS
More terms from Emeric Deutsch, Dec 18 2007
STATUS
approved