OFFSET
0,2
EXAMPLE
a(2)=6 because 1/tau(6)+1/tau(7)+1/tau(8) = 1/4+1/2+1/4 = 1.
MATHEMATICA
a[n_] := For[k=1, True, k++, If[Sum[1/DivisorSigma[0, k+i], {i, 0, n}]==1, Return[k]]]
k = 1; Table[While[Sum[1/DivisorSigma[0, k + i], {i, 0, n}] != 1, k++]; k, {n, 0, 12}] (* Jayanta Basu, Jul 01 2013 *)
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Benoit Cloitre, Aug 27 2002
EXTENSIONS
Edited by Dean Hickerson, Sep 03 2002
2 more terms from Ryan Propper, Sep 04 2005
a(14)-a(22) from Donovan Johnson, Jun 23 2010
STATUS
approved