OFFSET
1,1
COMMENTS
The corresponding indices k are listed in A121733.
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
Eric Weisstein's World of Mathematics, Ramanujan's Tau Function.
EXAMPLE
MATHEMATICA
Do[f=Mod[DivisorSigma[11, n], 691]; g=Mod[DivisorSigma[11, n+1], 691]; If[f==g, Print[{n, f}]], {n, 1, 10000}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Alexander Adamchuk, Aug 18 2006
STATUS
approved