a(n) = Sum_{k=0..n} binomial(n,k) * binomial(4*k,n-k).
A389225
a(n) = Sum_{k=0..n} binomial(n,k) * binomial(4*k,n-k).
Terms
- a(0) =1a(1) =1a(2) =9a(3) =43a(4) =233a(5) =1306a(6) =7371a(7) =42260a(8) =244329a(9) =1422655a(10) =8331034a(11) =49011084a(12) =289442363a(13) =1714910250a(14) =10188959132a(15) =60682788448a(16) =362173743273
External references
- oeis: A389225