%I #19 Sep 24 2023 19:01:03
%S 3,4,5,6,8,9,11,12,14,17,18,21,23,24,26,29,32,33,36,38,39,42,44,47,51,
%T 53,54,56,57,59,66,68,71,72,77,78,81,84,86,89,92,93,98,99,101,102,108,
%U 114,116,117,119,122,123,128,131,134,137,138,141,143,144,149,156,158
%N Number of conjugacy classes in PSL_2(p), p = prime(n).
%C A great deal is known about the number of conjugacy classes in the classical linear groups. See for example Dornhoff, Section 38, or Green.
%D Dornhoff, Larry, Group representation theory. Part A: Ordinary representation theory. Marcel Dekker, Inc., New York, 1971.
%H Robin Visser, <a href="/A124678/b124678.txt">Table of n, a(n) for n = 1..10000</a> (terms n = 1..270 from Klaus Brockhaus).
%H J. A. Green, <a href="https://doi.org/10.1090/S0002-9947-1955-0072878-2">The characters of the finite general linear groups</a>, Trans. Amer. Math. Soc., 80 (1955), 402-447.
%F a(n) = (prime(n) + 5)/2 for all n > 1. - _Robin Visser_, Sep 24 2023
%o (Magma) [ NumberOfClasses(PSL(2,p)) : p in [2,3,5,7,11,13,17,19,23,29,31,37] ];
%Y Cf. A000040, A000702, A006951, A124679, A124681.
%K nonn
%O 1,1
%A _N. J. A. Sloane_, Dec 25 2006
%E More terms from _Klaus Brockhaus_, Dec 26 2006