%I A051636
%S A051636 1,1,2,8,32,167,947,6974,53426,454682,4303532,50366912,553031624,
%T A051636 6760260236,90333982832,1369522152392,20986020606632,350528387240264,
%U A051636 5751957395258096,111685506968916032,2139383543480892032
%N A051636 Number of "labeled" cyclic subgroups of alternating group A_n.
%F A051636 a(n) = 1/2*Sum_{pi} (1+(-1)^(k_2+k_4+...)) * n!/(k_1!*1^k_1*k_2!*2^k_2*...*k_n!*n^k_n*phi(lcm{i:k_i 
               != 0})), where pi runs through all partitions k_1+2*k_2+...+n*k_n=n 
               and phi is Euler's function.
%Y A051636 Cf. A051625.
%Y A051636 Sequence in context: A030872 A030835 A137975 this_sequence A081561 A009753 
               A141202
%Y A051636 Adjacent sequences: A051633 A051634 A051635 this_sequence A051637 A051638 
               A051639
%K A051636 easy,nonn
%O A051636 1,3
%A A051636 Vladeta Jovovic (vladeta(AT)eunet.rs)