Number of n-length words w over ternary alphabet {1,2,3} such that for every prefix z of w we have 0<=#(z,1)-#(z,2)<=2 and 0<=#(z,2)-#(z,3)<=2 and #(z,x) gives the number of occurrences of letter x in z.
A225879
Number of n-length words w over ternary alphabet {1,2,3} such that for every prefix z of w we have 0<=#(z,1)-#(z,2)<=2 and 0<=#(z,2)-#(z,3)<=2 and #(z,x) gives the number of occurrences of letter x in z.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =3a(4) =7a(5) =14a(6) =23a(7) =51a(8) =102a(9) =167a(10) =371a(11) =742a(12) =1215a(13) =2699a(14) =5398a(15) =8839a(16) =19635a(17) =39270a(18) =64303a(19) =142843a(20) =285686a(21) =467799a(22) =1039171a(23) =2078342a(24) =3403199a(25) =7559883a(26) =15119766a(27) =24757991a(28) =54997523a(29) =109995046
External references
- oeis: A225879