Enumeration by block-type Enumeration formulae for mosaics Some numerical results

Some numerical results

Table 2 gives the numbers of D12-mosaics of type λ, (in this table the type 1,...,λn) of a partition is written in the form (1λ1,2λ2,...), where all terms with λi=0 are omitted) which were computed by using SYMMETRICA routines for the Redfield-cap operator.

 

Number of D12-mosaics in twelve tone music of type λ.
λ λ λ λ
(12) 1 (1,11) 1 (2,10) 6 (12,10) 6
(3,9) 12 (1,2,9) 30 (13,9) 12 (4,8) 29
(1,3,8) 85 (22,8) 84 (12,2,8) 140 (14,8) 29
(5,7) 38 (1,4,7) 170 (2,3,7) 340 (12,3,7) 340
(1,22,7) 510 (13,2,7) 340 (15,7) 38 (62) 35
(1,5,6) 236 (2,4,6) 610 (12,4,6) 610 (32,6) 424
(1,2,3,6) 2320 (13,3,6) 781 (23,6) 645 (12,22,6) 1820
(14,2,6) 610 (16,6) 50 (2,52) 386 (12,52) 386
(3,4,5) 1170 (1,2,4,5) 3480 (13,4,5) 1170 (1,32,5) 2330
(22,3,5) 3510 (12,2,3,5) 6960 (14,3,5) 1170 (1,23,5) 3500
(13,22,5) 3510 (15,2,5) 708 (17,5) 38 (43) 297
(1,3,42) 2915 (22,42) 2347 (12,2,42) 4470 (14,42) 792
(2,32,4) 5890 (12,32,4) 5890 (1,22,3,4) 17370 (13,2,3,4) 11580
(15,3,4) 1170 (24,4) 2325 (12,23,4) 8860 (14,22,4) 4463
(16,2,4) 610 (18,4) 29 (34) 713 (1,2,33) 7740
(13,33) 2610 (23,32) 6005 (12,22,32) 17630 (14,2,32) 5890
(16,32) 424 (1,24,3) 8725 (13,23,3) 11623 (15,22,3) 3510
(17,2,3) 340 (19,3) 12 (26) 554 (12,25) 2792
(14,24) 2325 (16,23) 645 (18,22) 84 (110,2) 6
(112) 1
A SYMMETRICA program for computing these numbers could be written as
main()
{
OP a,b,c,d;
anfang();
a=callocobject(); b=callocobject();
c=callocobject(); d=callocobject();
scan(INTEGER,a);
m_il_v(2L,b);
zykelind_Dn(a,S_V_I(b,0L));
/*
zykelind_Cn(a,b);
zykelind_Dn(a,b);
zykelind_aff1Zn(a,b);
*/
first_part_EXPONENT(a,c);
do
{
  zykelind_stabilizer_part(c,S_V_I(b,1L));
  /* computes the cycle index of the stabilizer of a partition
  of type a */
  redf_cap(b,d);
  /* computes the Redfield cap of the cycle indices, which occur
  in the vector b */
  printf(" The number of mosaics of type ");
  print(c);
  printf(" is ");
  println(d); 
} while (next(c,c)); /* lists all possible types of partitions */
freeall(a); freeall(b); freeall(c); freeall(d);
ende();
}

If n is even then a mosaic consisting of two blocks of size n/2 corresponds to a trope introduced by Hauer. By applying the power group enumeration theorem [8] an explicit formula for the number of all orbits of tropes under a group action was determined in [4].


harald.fripertinger "at" uni-graz.at, May 10, 2016

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