OFFSET
1,2
COMMENTS
For prime numbers, the sum of their aliquot divisors is exactly 1 = 1^3.
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000 (terms 1..2500 from Harvey P. Dale)
EXAMPLE
a(6) = 10, since the sum of aliquot divisors 1 + 2 + 5 = 8 = 2^3.
MAPLE
for n do s:=numtheory[sigma](n)-n; if root(s, 3)=trunc(root(s, 3)) then print(n); fi; od:
MATHEMATICA
Select[Range[250], IntegerQ[Power[DivisorSigma[1, #]-#, (3)^-1]]&] (* Harvey P. Dale, Nov 25 2011 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Martin Renner, Oct 13 2011
STATUS
approved