Number of chiral pairs of color patterns (set partitions) for a row of length n using 4 or fewer colors (subsets).

A320934

Number of chiral pairs of color patterns (set partitions) for a row of length n using 4 or fewer colors (subsets).

Terms

    a(0) =0a(1) =0a(2) =1a(3) =4a(4) =20a(5) =80a(6) =336a(7) =1344a(8) =5440a(9) =21760a(10) =87296a(11) =349184a(12) =1397760a(13) =5591040a(14) =22368256a(15) =89473024a(16) =357908480a(17) =1431633920a(18) =5726601216a(19) =22906404864a(20) =91625881600a(21) =366503526400

External references