%I M0245 N0085 #26 Oct 22 2023 21:27:04

%S 1,1,2,2,3,2,3,4,2,2,7,2,6,9,2,2,3,2,4,2,5,2,3,3,5,2,2,3,6,3,9,3,3,4,

%T 2,5,5,4,2,2,3,2,2,5,2,2,4,9,3,6,3,2,7,3,3,2,2,2,5,3,6,2,7,2,10,2,5,

%U 10,3,2,3,2,2,2,4,2,2,5,3,21,3,2,5,5,5,3,3,13,2,2,3,2,2,4,5,2,2,3,4,2,4,2,3

%N Least negative primitive root of n-th prime.

%D M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards Applied Math. Series 55, 1964 (and various reprintings), p. 864.

%D N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).

%D N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

%H T. D. Noe, <a href="/A002199/b002199.txt">Table of n, a(n) for n=1..10000</a>

%H M. Abramowitz and I. A. Stegun, eds., <a href="http://www.convertit.com/Go/ConvertIt/Reference/AMS55.ASP">Handbook of Mathematical Functions</a>, National Bureau of Standards, Applied Math. Series 55, Tenth Printing, 1972 [alternative scanned copy].

%H A. E. Western and J. C. P. Miller, <a href="/A002223/a002223.pdf">Tables of Indices and Primitive Roots</a>, Royal Society Mathematical Tables, Vol. 9, Cambridge Univ. Press, 1968 [Annotated scans of selected pages]

%F a(n) = prime(n) - A071894(n). - _T. D. Noe_, Oct 24 2005

%t Table[(k=-1;While[MultiplicativeOrder[k,p]!=p-1,k--];-k),{p,Prime@Range@100}] (* _Giorgos Kalogeropoulos_, Sep 28 2023 *)

%Y Cf. A060749, A001918.

%K nonn

%O 1,3

%A _N. J. A. Sloane_