OFFSET
0,2
COMMENTS
At order 24, the two groups which achieve the maximum derived length are S_4 and SL(2,3). At order 48, a group which achieves the maximum derived length is GL(2,3). At order 432, the only group which achieves the maximum derived length is 3^2:GL(2,3).
There are three groups of order 1296 achieving maximal derived length. - Charles R Greathouse IV, May 26 2014
FORMULA
a(n) >= 2*a(n-1). - Charles R Greathouse IV, May 26 2014
EXAMPLE
a_2=6 because the smallest solvable group with derived length 2 is the symmetric group S_3, which has order 6.
PROG
(GAP) a := function(arg)
local n, size, gr;
n := arg[1];
if Length(arg) > 1 then
size := arg[2];
else
size := 1;
fi;
gr := OneSmallGroup(Size, size, DerivedLength, n);
if gr <> fail then
return size;
else
return a(n, size + 1);
fi;
end; # Charles R Greathouse IV, May 23 2014
CROSSREFS
KEYWORD
nice,nonn,hard,more
AUTHOR
David L. Harden, Mar 31 2005
EXTENSIONS
a(6) from Charles R Greathouse IV, May 26 2014
STATUS
approved