Number of step cyclic shifted sequences using a maximum of three different symbols.

Terms

a(0) =3a(1) =6a(2) =10a(3) =21a(4) =24a(5) =92a(6) =78a(7) =327a(8) =443a(9) =1632a(10) =1698a(11) =12769a(12) =10464a(13) =57840a(14) =122822a(15) =348222a(16) =476052a(17) =3597442a(18) =3401970a(19) =22006959a(20) =41597374a(21) =142677588a(22) =186077886a(23) =1476697627a(24) =1694658003a(25) =8147282460a(26) =15690973754a(27) =68149816689a(28) =84520682160a(29) =857935531804