OFFSET
1,2
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..1000
Max Alekseyev, PARI/GP Scripts for Miscellaneous Math Problems (invphi.gp).
MATHEMATICA
f[x_] := Count[Table[EulerPhi[j]-EulerPhi[x], {j, 1, x}], 0] t=Table[0, {50}]; Do[s=f[n]; If[s<51&&t[[s]]==0, t[[s]]=n], {n, 1, 4000}]; t
PROG
(PARI) lista(len) = {my(v = vector(len), c = 0, k = 1, i); while(c < len, i = #select(x -> x <= k, invphi(eulerphi(k))); if(i <= len && v[i] == 0, c++; v[i] = k); k++); v; } \\ Amiram Eldar, Nov 08 2024, using Max Alekseyev's invphi.gp
CROSSREFS
KEYWORD
nonn
AUTHOR
Labos Elemer, Mar 24 2003
STATUS
approved