Number of primitive (aperiodic) step shifted (decimated) sequences using exactly four different symbols.

A056388

Number of primitive (aperiodic) step shifted (decimated) sequences using exactly four different symbols.

Terms

    a(0) =0a(1) =0a(2) =0a(3) =12a(4) =60a(5) =792a(6) =1404a(7) =10704a(8) =31200a(9) =204972a(10) =349956a(11) =3727128a(12) =5065804a(13) =41572908a(14) =127198968a(15) =517279416a(16) =1041517620a(17) =11195605728a(18) =15012935676a(19) =135825494568a(20) =363040468328

External references