Number of words, either empty or beginning with the first letter of the ternary alphabet, where each letter of the alphabet occurs n times and letters of neighboring word positions are equal or neighbors in the alphabet.

A208675

Number of words, either empty or beginning with the first letter of the ternary alphabet, where each letter of the alphabet occurs n times and letters of neighboring word positions are equal or neighbors in the alphabet.

Terms

    a(0) =1a(1) =1a(2) =5a(3) =37a(4) =309a(5) =2751a(6) =25493a(7) =242845a(8) =2360501a(9) =23301307a(10) =232834755a(11) =2349638259a(12) =23905438725a(13) =244889453043

External references