OFFSET
1,2
COMMENTS
Assumes that A090240 is correct.
MATHEMATICA
f[n_] := (n*DivisorSigma[0, n]/DivisorSigma[1, n]); a = Table[0, {50}]; Do[ b = f[n]; If[ IntegerQ[b] && b < 51 && a[[b]] == 0, a[[b]] = n], {n, 1, 10 ^7}]; a
CROSSREFS
KEYWORD
nonn
AUTHOR
Robert G. Wilson v and R. K. Guy, Feb 11 2004
STATUS
approved