OFFSET
1,2
COMMENTS
Sequence is probably a permutation of the positive integers.
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
MAPLE
A[1]:= 1: A[2]:= 2: A[3]:= 3:
S:= {$4..500}:
for n from 4 do
P:= numtheory:-factorset(A[n-2]);
for s in S do
if member(igcd(s, A[n-2]), P) then
A[n]:= s; S:= S minus {s}; break
fi
od;
if not assigned(A[n]) then break fi
od:
seq(A[i], i=1..n-1); # Robert Israel, Jan 04 2023
MATHEMATICA
f[s_] := Block[{k = 1}, While[MemberQ[s, k] || ! PrimeQ[GCD[s[[ -2]], k]], k++ ]; Append[s, k] ]; Nest[f, {1, 2, 3}, 70] (* Ray Chandler, Sep 05 2006 *)
CROSSREFS
KEYWORD
nonn,look
AUTHOR
Leroy Quet, Aug 31 2006
EXTENSIONS
Corrected and extended by Ray Chandler, Sep 05 2006
STATUS
approved