OFFSET
-2,1
COMMENTS
Although pi takes all values, solutions are not guaranteed since nontotient numbers exist.
First possible holes (k>10^6) are for n = -3, 63, 73, 144, 162, 185, 204, 228, 233, 256, 264,...
EXAMPLE
n=13: Phi[13]=12, Pi[13]=6, a[12-6]=a(6)=13; n=63: no solution was found at x<=1000000.
MATHEMATICA
Do[k = 1; While[ EulerPhi[k] != PrimePi[k] + n, k++ ]; Print[k], {n, -2, 62}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Labos Elemer, Aug 02 2002
EXTENSIONS
Edited by Robert G. Wilson v, Aug 12 2002
STATUS
approved