OFFSET
1,1
EXAMPLE
a(5) cannot be 12 because 8 and 12 are not relatively prime
MATHEMATICA
f[s_] := Block[{k = 2 s[[ -1]] - s[[ -2]] + 1}, While[ GCD[k, s[[ -1]]] > 1, k++ ]; Append[s, k]]; Rest@ Nest[f, {2, 2}, 51] (* Robert G. Wilson v, Jun 09 2010 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
J. Lowell, Jun 08 2010
EXTENSIONS
a(11) onwards from Robert G. Wilson v, Jun 09 2010
STATUS
approved