|
%I #14 Jan 13 2022 21:49:45
%S 0,1,1,1,2,4,1,6,5,3,5,6,3,13,11,10,5,5,10,8,9,16,19,11,16,10,22,13,
%T 23,12,15,30,9,35,8,17,15,46,41,37,14,34,20,36,16,10,21,49,26,54,43,
%U 17,38,64,71,65,23,32,33,22,71,30,56,28,77,16,26,79,38,74
%N Let p be the n-th odd prime; a(n) is the number of primitive roots of p which are relatively prime to p-1.
%C The number of primitive roots without the restriction of relative primality is in A008330, so a(n) <= A008330(n+1). A table of prime moduli is in A128250. - _R. J. Mathar_, Oct 31 2007
%D R. Osborn, Tables of All Primitive Roots of Odd Primes Less Than 1000, Univ. Texas Press, Austin, TX, 1961, pp. 69-70.
%H T. D. Noe, <a href="/A128860/b128860.txt">Table of n, a(n) for n = 1..1000</a>
%p A128250 := proc(g,p) local k ; if gcd(g,p) > 1 then RETURN(0) ; fi ; for k from 1 do if (g^k mod p ) = 1 then RETURN(k) ; fi ; od: end: proots := proc(p) local a,g ; a := 0 ; for g from 1 to p do if A128250(g,p) = p-1 and gcd(g,p-1) = 1 then a := a+1 ; fi ; od: RETURN(a) ; end: A128860 := proc(n) local p; p := ithprime(n+1) ; proots(p) ; end: seq(A128860(n),n=1..60) ; # _R. J. Mathar_, Oct 31 2007
%K nonn,easy
%O 1,5
%A _N. J. A. Sloane_, Apr 20 2007
%E More terms from _R. J. Mathar_, Oct 31 2007
|
