a(n) is the number of strings of length n over the alphabet {a,b,c} with the number of a's divisible by 3, and the number of b's and c's is at most 3.
A340169
a(n) is the number of strings of length n over the alphabet {a,b,c} with the number of a's divisible by 3, and the number of b's and c's is at most 3.
Terms
- a(0) =1a(1) =2a(2) =4a(3) =9a(4) =8a(5) =40a(6) =161a(7) =14a(8) =112a(9) =673a(10) =20a(11) =220a(12) =1761a(13) =26a(14) =364a(15) =3641a(16) =32a(17) =544a(18) =6529a(19) =38a(20) =760a(21) =10641a(22) =44a(23) =1012a(24) =16193a(25) =50a(26) =1300a(27) =23401a(28) =56a(29) =1624
External references
- oeis: A340169