OFFSET
1,2
COMMENTS
For every k>=0, every (3k+1)-th term is square, because a triple of terms with {odd,even,even} number of divisors must be followed by a similar triple.
MATHEMATICA
coQ[n_, m_]:=CoprimeQ[DivisorSigma[0, n], DivisorSigma[0, m]];
f[x_, y_, z_]:=Sort[{coQ[x, y], coQ[x, z], coQ[y, z]}];
next[n_, m_]:=Module[{k=m+1}, While[f[n, m, k]!={False, True, True}, k++]; k];
a[1]=1; a[2]=2; a[n_]:=a[n]=next[a[n-2], a[n-1]]; a/@Range[102]
CROSSREFS
KEYWORD
nonn
AUTHOR
Ivan N. Ianakiev, Jul 23 2022
STATUS
approved