OFFSET
1,2
COMMENTS
LINKS
T. D. Noe, Table of n, a(n) for n = 1..1000
EXAMPLE
39 is in the sequence because sopf(39) = 16 and sopf(39 + sopf(39)) = sopf(55 ) = 16.
MATHEMATICA
d[n_] := Plus @@ Transpose[FactorInteger[n]][[1]]; Join[{1}, Select[Range[2, 50000], d[# + d[#]] == d[#] &]]
CROSSREFS
KEYWORD
nonn
AUTHOR
Michel Lagneau, Aug 28 2010
STATUS
approved