OFFSET
1,1
EXAMPLE
MATHEMATICA
f[n_] := Plus @@ (-(d = Divisors[n])*(-1)^(Range[Length[d], 1, -1])); seqQ[n_]:=Plus @@ FixedPointList[f, n] == 3n + 1; Select[Range[10000], seqQ]
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Amiram Eldar, Mar 13 2020
STATUS
approved