This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A060615 #6 Jul 02 2025 16:02:01 %S A060615 3,8,15,24,48,63,80,120,168,255,288,360,528,624,728,840,960,1023,1368, %T A060615 1680,1848,2208,2400,2808,3480,3720,4095,4488,5040,5328,6240,6560, %U A060615 6888,7920,9408,10200,10608,11448,11880,12768,14640,15624,16128,16383,17160 %N A060615 Number of conjugacy classes in the group GL_2(K) when K is a finite field with q = p^m for a prime p and m >= 1. %C A060615 The number of conjugacy classes in the group GL_2(K) is q^2 - 1 so this sequence is a subsequence of A005563 restricted to q = prime power. The order of the group GL_2(K) is in A059238. %F A060615 a(n) = A000961(n+2)^2 - 1. - _Sean A. Irvine_, Dec 04 2022 %p A060615 with(numtheory): for n from 2 to 400 do if nops(ifactors(n)[2]) = 1 then printf(`%d,`, n^2-1) fi: od: %Y A060615 A000961, A005563, A059238. A diagonal of A060638. %K A060615 nonn %O A060615 0,1 %A A060615 Ahmed Fares (ahmedfares(AT)my-deja.com), Apr 13 2001 %E A060615 More terms from _James Sellers_, Apr 14 2001