a(n) is the number of words of length n over the alphabet {a,b,c} with an even number of appearances of the letter 'a' and the sum of appearances of the letters 'b' and 'c' add up to at most 3.
A341896
a(n) is the number of words of length n over the alphabet {a,b,c} with an even number of appearances of the letter 'a' and the sum of appearances of the letters 'b' and 'c' add up to at most 3.
Terms
- a(0) =1a(1) =2a(2) =5a(3) =14a(4) =25a(5) =90a(6) =61a(7) =294a(8) =113a(9) =690a(10) =181a(11) =1342a(12) =265a(13) =2314a(14) =365a(15) =3670a(16) =481a(17) =5474a(18) =613a(19) =7790a(20) =761a(21) =10682a(22) =925a(23) =14214a(24) =1105a(25) =18450a(26) =1301a(27) =23454a(28) =1513a(29) =29290
External references
- oeis: A341896