a(n) = number of Yamanouchi words over the alphabet {1, 2, 3} of length n that start with 3.

A369591

a(n) = number of Yamanouchi words over the alphabet {1, 2, 3} of length n that start with 3.

Terms

    a(0) =0a(1) =0a(2) =1a(3) =2a(4) =5a(5) =14a(6) =35a(7) =90a(8) =245a(9) =644a(10) =1716a(11) =4707a(12) =12727a(13) =34683a(14) =96174a(15) =264784a(16) =732785a(17) =2051338a(18) =5719684a(19) =16007081a(20) =45160093a(21) =127106181a(22) =358743903a(23) =1018566177a(24) =2887666445a(25) =8204375034

External references