Number of strings of length n on three symbols containing all permutations of those three symbols as substrings (factors), divided by six.

A188428

Number of strings of length n on three symbols containing all permutations of those three symbols as substrings (factors), divided by six.

Terms

    a(0) =0a(1) =0a(2) =0a(3) =0a(4) =0a(5) =0a(6) =0a(7) =0a(8) =1a(9) =9a(10) =54a(11) =276a(12) =1282a(13) =5585a(14) =23223a(15) =93146a(16) =362928a(17) =1380535a(18) =5145692a(19) =18846775a(20) =67982489a(21) =241940204a(22) =850777688a(23) =2959796467a(24) =10197732687a(25) =34828459508a(26) =118003182174a(27) =396897710483

External references