OFFSET
1,1
COMMENTS
The difference between any two terms is == 0 (mod 7).
MATHEMATICA
f[s_List] := Select[ Union@ Join[s, Union[1 + Times @@@ Subsets[ Join[s, s], {2}]]], # < 10000 &]; Nest[f, {3}, 8]
CROSSREFS
KEYWORD
nonn
AUTHOR
Robert G. Wilson v, Sep 04 2010
STATUS
approved