OFFSET
1,2
FORMULA
f[n_]=Mod[E*n, 1] g[x_]:=-1/;0<=x<=1/3 g[x_]:=0/;1/3<x<=2/3 g[x_]:=11/;1/3<x<=1 a(n)=n If N[f[n+2]-2*f[n+1]+f[n]]-g[f[n+1]]==0
MATHEMATICA
f[n_]=Mod[E*n, 1]; digits=200; (* uneven Cantor type function*); g[x_]:=-1/ ; 0<=x<=1/3; g[x_]:=0/; 1/3<x<=2/3; g[x_]:=11/; 1/3<x<=1; a=Delete[Union[Table[If [N[f[n+2]-2*f[n+1]+f[n]]-g[f[n+1]]==0, n, 0], {n, 1, digits}]], 1]
CROSSREFS
KEYWORD
nonn
AUTHOR
Roger L. Bagula, Sep 09 2004
EXTENSIONS
Edited by N. J. A. Sloane, May 08 2007
STATUS
approved