Number of chiral pairs of color loops of length n with exactly 4 different colors.

A305543

Number of chiral pairs of color loops of length n with exactly 4 different colors.

Terms

    a(0) =0a(1) =0a(2) =0a(3) =3a(4) =24a(5) =124a(6) =588a(7) =2487a(8) =10240a(9) =40488a(10) =158220a(11) =609078a(12) =2333520a(13) =8895204a(14) =33864364a(15) =128793627a(16) =490027200a(17) =1865625340a(18) =7110959340a(19) =27138210888a(20) =103717720000a(21) =396965694444

External references