OFFSET
1,2
MATHEMATICA
digits=30000;
Hofstadter[n_Integer?Positive] := Hofstadter[n] = Hofstadter[n - Hofstadter[n-1]] + Hofstadter[n - Hofstadter[n-2]];
Hofstadter[1] = Hofstadter[2] = 1;
a1=Table[Hofstadter[n], {n, 1, digits}];
b=Table[If[a1[[n]]-a1[[n-1]]==0, a1[[n]], 0], {n, 2, digits}];
c=Delete[Union[b], 1]
CROSSREFS
KEYWORD
nonn
AUTHOR
Roger L. Bagula, Sep 29 2003
STATUS
approved