Number of step cyclic shifted sequence structures using a maximum of two different symbols.

Terms

a(0) =1a(1) =2a(2) =2a(3) =4a(4) =3a(5) =8a(6) =5a(7) =14a(8) =11a(9) =26a(10) =15a(11) =88a(12) =37a(13) =130a(14) =184a(15) =357a(16) =261a(17) =1346a(18) =805a(19) =3760a(20) =4434a(21) =9758a(22) =8385a(23) =47462a(24) =33781a(25) =108330a(26) =138767a(27) =408376a(28) =331185a(29) =2251816