A297567 Number of nonisomorphic proper colorings of partition star graph using three colors.
3, 6, 9, 12, 12, 24, 24, 15, 36, 30, 48, 48, 18, 48, 60, 72, 96, 96, 96, 21, 60, 90, 60, 96, 192, 108, 144, 192, 192, 192, 24, 72, 120, 120, 120, 288, 240, 216, 192, 384, 384, 288, 384, 384, 384, 27, 84, 150, 180, 105, 144, 384, 480, 324, 432, 240, 576, 480, 768, 408, 384, 768, 768, 576, 768, 768, 768, 30, 96, 180, 240, 210, 168, 480, 720, 480, 432, 864, 360, 288, 768, 960, 1152, 1536, 816, 480, 1152, 960, 1536, 1536, 768
Offset: 0
Examples
Rows are: 3; 6; 9, 12; 12, 24, 24; 15, 36, 30, 48, 48; 18, 48, 60, 72, 96, 96, 96;
Links
- Marko Riedel et al., Orbital chromatic polynomials
- Marko Riedel, Maple code computing OCP for sequences A297567, A297568, A297569, A297570.
Programs
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Maple
b:= (n, i)-> `if`(n=0, [3], `if`(i<1, [], [seq(map(x-> x* binomial(2^i+j-1, j), b(n-i*j, i-1))[], j=0..n/i)])): T:= n-> b(n$2)[]: seq(T(n), n=0..10); # Alois P. Heinz, Jan 14 2018
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Mathematica
b[n_, i_] := If[n == 0, {3}, If[i<1, {}, Table[Map[Function[x, x*Binomial[ 2^i + j - 1, j]], b[n - i*j, i - 1]], {j, 0, n/i}]] // Flatten]; T[n_] := b[n, n]; Table[T[n], {n, 0, 10}] // Flatten (* Jean-François Alcover, Jan 17 2018, after Alois P. Heinz *)
Formula
For a partition lambda we have the OCP: k Product_{p^v in lambda} C((k-1)^p+v-1, v). Here we have k=3.
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