OFFSET
1,2
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..1000
EXAMPLE
For n = 1, max(tau(1),tau(2),tau(3)) - min(tau(1),tau(2),tau(3)) = max(1,2,2) - min(1,2,2) = 1.
For n = 121, max(tau(121),tau(122),tau(123)) - min(tau(121),tau(122),tau(123)) = max(1,2,2) - min(1,2,2) = 1
MAPLE
with(numtheory):for n from 1 to 1500000 do; if max(tau(n), tau(n+1), tau(n+2))- min(tau(n), tau(n+1), tau(n+2))= 1 then print(n); else fi ; od;
MATHEMATICA
Select[Range[10^6], Max[(d = DivisorSigma[0, #+{0, 1, 2}])] - Min[d] == 1 &] (* Amiram Eldar, Aug 14 2019 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Michel Lagneau, Feb 11 2010, Feb 13 2010
STATUS
approved