login
A182606
Number of conjugacy classes in GL(n,13).
18
1, 12, 168, 2184, 28548, 371112, 4826640, 62746152, 815728368, 10604468628, 137858461104, 1792159992168, 23298084722808, 302875101365928, 3937376380474992, 51185892946146672, 665416609115237772, 8650415918497693704, 112455406951074120024
OFFSET
0,2
LINKS
FORMULA
G.f.: Product_{k>=1} (1-x^k)/(1-13*x^k). - Alois P. Heinz, Nov 03 2012
MAPLE
with(numtheory):
b:= proc(n) b(n):= add(phi(d)*13^(n/d), d=divisors(n))/n-1 end:
a:= proc(n) a(n):= `if`(n=0, 1,
add(add(d*b(d), d=divisors(j)) *a(n-j), j=1..n)/n)
end:
seq(a(n), n=0..30); # Alois P. Heinz, Nov 03 2012
MATHEMATICA
b[n_] := Sum[EulerPhi[d]*13^(n/d), {d, Divisors[n]}]/n-1; a[n_] := a[n] = If[n == 0, 1, Sum[Sum[d*b[d], {d, Divisors[j]}]*a[n-j], {j, 1, n}]/n]; Table[a[n], {n, 0, 30}] (* Jean-François Alcover, Feb 17 2014, after Alois P. Heinz *)
PROG
(Magma) /* The program does not work for n>5: */ [1] cat [NumberOfClasses(GL(n, 13)): n in [1..5]];
(PARI)
N=66; x='x+O('x^N);
gf=prod(n=1, N, (1-x^n)/(1-13*x^n) );
v=Vec(gf)
/* Joerg Arndt, Jan 24 2013 */
KEYWORD
nonn
AUTHOR
Klaus Brockhaus, Nov 23 2010
EXTENSIONS
More terms from Alois P. Heinz, Nov 03 2012
MAGMA code edited by Vincenzo Librandi, Jan 24 2013
STATUS
approved