a(n) = Sum_{k=0..floor(n/3)} binomial(n-2*k,k) * binomial(2*(n-2*k),n-2*k).
A360266
a(n) = Sum_{k=0..floor(n/3)} binomial(n-2*k,k) * binomial(2*(n-2*k),n-2*k).
Terms
- a(0) =1a(1) =2a(2) =6a(3) =22a(4) =82a(5) =312a(6) =1210a(7) =4752a(8) =18834a(9) =75184a(10) =301856a(11) =1217604a(12) =4930626a(13) =20032052a(14) =81615072a(15) =333328532a(16) =1364264250a(17) =5594210292a(18) =22977466864a(19) =94517423444a(20) =389316529512
External references
- oeis: A360266