a(n) = Sum_{k=0..n} (k+1)*binomial(3*n-4*k+1,n-k)/(n-k+1).
A279159
a(n) = Sum_{k=0..n} (k+1)*binomial(3*n-4*k+1,n-k)/(n-k+1).
Terms
- a(0) =1a(1) =4a(2) =13a(3) =47a(4) =202a(5) =982a(6) =5119a(7) =27819a(8) =155545a(9) =888517a(10) =5162089a(11) =30406466a(12) =181164254a(13) =1089858766a(14) =6610791274a(15) =40386823863a(16) =248278003097
External references
- oeis: A279159