Number of words of length n over an alphabet of size 4 that are not "bifix-free".
A094559
Number of words of length n over an alphabet of size 4 that are not "bifix-free".
Terms
- a(0) =0a(1) =0a(2) =4a(3) =16a(4) =76a(5) =304a(6) =1264a(7) =5056a(8) =20404a(9) =81616a(10) =327184a(11) =1308736a(12) =5237776a(13) =20951104a(14) =83815744a(15) =335262976a(16) =1341097036a(17) =5364388144a(18) =21457733104a(19) =85830932416a(20) =343324451056
External references
- oeis: A094559