OFFSET
1,2
COMMENTS
Same as A122544, except that a(n) is allowed to take values already in the sequence.
LINKS
Alois P. Heinz, Table of n, a(n) for n = 1..1000
MATHEMATICA
f[s_] := Block[{n, k}, k = n = Length[s] + 1; While[MemberQ[Union[Plus @@@ Tuples[s, 2]], k], k += n]; Append[s, k]]; Nest[f, {1}, 60]
CROSSREFS
KEYWORD
nonn
AUTHOR
Ray Chandler, Sep 23 2006
STATUS
approved