a(n) = Sum_{k=0..n} binomial(4*n+3*k,n-k).
A390409
a(n) = Sum_{k=0..n} binomial(4*n+3*k,n-k).
Terms
- a(0) =1a(1) =5a(2) =40a(3) =344a(4) =3046a(5) =27398a(6) =248857a(7) =2275452a(8) =20906144a(9) =192779081a(10) =1782715547a(11) =16523337885a(12) =153436815280
External references
- oeis: A390409