A212360 - OEIS

%I #19 Jan 14 2013 21:58:58

%S 1,2,1,3,6,2,4,12,12,36,6,5,20,40,120,180,240,24,6,30,90,60,300,1200,

%T 320,1200,2700,1800,120,7,42,126,210,630,3150,2100,3150,4200,25200,

%U 12600,12600,37800,15120,720,8,56,224,392,280,1176,7056,11760,9072,11760,11760,88200,58800,176400,22260,58800,470400,352800,141120,529200,141120,5040

%N Partition array a(n,k) with the total number of necklaces (C_n symmetry) with n beads, each available in n colors, with color signature given by the k-th partition of n in Abramowitz-Stegun(A-St) order.

%C This array is obtained by multiplying the entry of the array A212359(n,k) (number of necklaces (C_n symmetry) with n beads, each available in n colors, with color representative given by the n-multiset representative obtained from the k-th partition of n in A-St order after 'exponentiation') with the entry of the array A035206(n,k) (number of members in the equivalence class represented by the color multiset considered for A212359(n,k)):  a(n,k)=A212359(n,k)* A035206(n,k), k=1..p(n)= A000041(n), n>=1. The row sums then give the total number of necklaces with beads from n colors, given by A056665(n).

%C See A212359 for references, the 'exponentiation', and a link.

%C The corresponding triangle with the summed row entries which belong to partitions of n with fixed number of parts is A213935. [From _Wolfdieter Lang_, Jul 12 2012]

%H Wolfdieter Lang, <a href="/A212360/a212360.pdf">Rows n=1..15.</a>

%F a(n,k) = A212359(n,k)*A035206(n,k), k=1,2,...,p(n)= A000041(n), n>=1.

%e n\k  1   2   3   4    5     6    7     8     9    10   11

%e 1    1

%e 2    2   1

%e 3    3   6   2

%e 4    4  12  12  36    6

%e 5    5  20  40 120  180   240   24

%e 6    6  30  90  60  300  1200  320  1200  2700  1800  120

%e ...

%e See the link for the rows n=1..15.

%e a(3,1)=3 because the 3 necklaces with 3 beads coming in 3 colors have the color multinomials (here monomials)  c[1]^3=c[1]*c[1]*c[1], c[2]^3 and c[3]^3. The partition of 3 is 3, the color representative is c[1]^3, and the equivalence class with color signature from the partition 3 has the three given members.

%e a(3,2)=6 from the color signature 2,1 with the representative multinomial c[1]^2 c[2] with coefficient A212359(3,2)=1, the only 3-necklace cyclic(112) (taking j for the color  c[j]), and  A035206(3,2)=6 members of the whole color equivalence class: cyclic(112), cyclic(113),  cyclic(221), cyclic(223), cyclic(331) and cyclic(332).

%e a(3,3)=2, color signature 1^3=1,1,1 with representative multinomial  c[1]*c[2]*c[3] with coefficient A212359(3,3)=2 from the two necklaces cyclic(1,2,3) and cyclic (1,3,2). There are no other members in this class (A035206(3,3)=1).

%e The sum of row nr. 3 is 11=A056665(3). See the example given there with c[1]=R, c[2]=G and c[3]=B.

%Y Cf. A212359, A035206, A056665, A213935.

%K nonn,tabf

%O 1,2

%A _Wolfdieter Lang_, Jun 25 2012