a(n) = Sum_{k=0..n} (-1)^(n-k) * binomial(5*k,k) / (4*k + 1).
A346681
a(n) = Sum_{k=0..n} (-1)^(n-k) * binomial(5*k,k) / (4*k + 1).
Terms
- a(0) =1a(1) =0a(2) =5a(3) =30a(4) =255a(5) =2275a(6) =21476a(7) =210404a(8) =2120041a(9) =21830314a(10) =228713056a(11) =2430255074a(12) =26128088701a(13) =283703487059
External references
- oeis: A346681