Search: id:A133777 Results 1-1 of 1 results found. %I A133777 %S A133777 1,1,1,2,15,47,840 %N A133777 Number of isomorphism types of groups of order n!. %C A133777 This sequence is interesting in view of Cayley's theorem which says that every finite group with n elements is isomorphic to a subgroup of the symmetric group S_n whose number of elements is n!. Therefore a(n) - 1 gives the number of groups "competing" with S_n in this respect. The eighth term, a(7), i.e. the number of isomorphism types of groups of order 7!=5040, seems to be unknown. %D A133777 http://www-public.tu-bs.de:8080/~hubesche/number.html %H A133777 Hans Ulrich Besche, Number of isomorphism types of finite groups of given order %e A133777 a(0)=1 because 0!=1 and there is exactly one group of order one up to isomorphism %Y A133777 Sequence in context: A152015 A162256 A041719 this_sequence A025213 A116693 A154565 %Y A133777 Adjacent sequences: A133774 A133775 A133776 this_sequence A133778 A133779 A133780 %K A133777 hard,nonn %O A133777 0,4 %A A133777 Peter C. Heinig (algorithms(AT)gmx.de), Jan 02 2008 Search completed in 0.001 seconds