OFFSET
0,2
COMMENTS
A110412: Sum_{d<n is a divisor of n} tau(n-d).
Found zeros < 7500 only for 12 & 20.
MATHEMATICA
f[n_] := Plus @@ (DivisorSigma[0, n - # ] & /@ Most[Divisors[n]]); t = Table[0, {100}]; Do[a = f[n]; If[a < 100 && t[[a + 1]] == 0, t[[a + 1]] = n; Print[{a, n}]], {n, 630}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Amarnath Murthy and Robert G. Wilson v, Aug 09 2005
STATUS
approved