OFFSET
1,1
EXAMPLE
MATHEMATICA
f[p_, e_] := Sum[(-1)^(e - k)*p^k, {k, 0, e}]; s[1] = 1; s[n_] := s[n] = Times @@ (f @@@ FactorInteger[n]); Select[Range[1000], Plus @@ FixedPointList[s, #] == 2 # + 1 &]
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Amiram Eldar, Jan 06 2020
STATUS
approved