OFFSET
1,2
COMMENTS
The last to appear is 1,2,3,5,8,9,10,11,15,18,19,21,22,25,30,34,42,45,46,58,69,70,81,90,126,133,158,202,276,465,...,.
MATHEMATICA
f[n_] := Plus @@ (DivisorSigma[0, n - # ] & /@ Most[Divisors[n]]); t = Table[0, {1000}]; Do[a = f[n]; If[a < 1000 && t[[a + 1]] == 0, t[[a + 1]] = n; Print[{a, n}]], {n, 10^6}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Amarnath Murthy and Robert G. Wilson v, Aug 09 2005
STATUS
approved