A180432 Start with 3. If a, b in sequence, so is ab+1.

3, 10, 31, 94, 101, 283, 304, 311, 850, 913, 934, 941, 962, 1011, 2551, 2740, 2803, 2824, 2831, 2887, 2915, 3034, 3041, 3111, 3132, 7654, 8221, 8410, 8473, 8494, 8501, 8662, 8746, 8774, 8837, 9103, 9124, 9131, 9334, 9341, 9397, 9411, 9425, 9495, 9621

Offset: 1

Author

Robert G. Wilson v, Sep 04 2010

Keywords

• nonn

Comments

The difference between any two terms is == 0 (mod 7).

Crossrefs

Cf. A009293.

Programs

Mathematica

f[s_List] := Select[ Union@ Join[s, Union[1 + Times @@@ Subsets[ Join[s, s], {2}]]], # < 10000 &]; Nest[f, {3}, 8]