Number of step cyclic shifted sequence structures using exactly three different symbols.

Terms

a(0) =0a(1) =0a(2) =1a(3) =2a(4) =3a(5) =14a(6) =11a(7) =52a(8) =72a(9) =274a(10) =281a(11) =2155a(12) =1741a(13) =9650a(14) =20456a(15) =58071a(16) =79293a(17) =599452a(18) =566739a(19) =3668218a(20) =6931312a(21) =23776154a(22) =31008623a(23) =246109051a(24) =282422552a(25) =1357819070a(26) =2615067966a(27) =11358104142