Number of squarefree words of length n in a 7-ary alphabet, with new values 0..6 introduced in increasing order.

A215073

Number of squarefree words of length n in a 7-ary alphabet, with new values 0..6 introduced in increasing order.

Terms

    a(0) =1a(1) =1a(2) =2a(3) =4a(4) =12a(5) =40a(6) =154a(7) =659a(8) =3085a(9) =15438a(10) =81200a(11) =442206a(12) =2465945a(13) =13968206a(14) =79933735a(15) =460447075a(16) =2663586832a(17) =15450089345a(18) =89773528848a(19) =522212524474

External references