a(n) = Sum_{k=0..n}((binomial(2*k,k)*Sum_{i=0..n-k}(binomial(k+1,n-k-i)*binomial(k+i,k)))/(k+1)^2)*(n+1).
A270661
a(n) = Sum_{k=0..n}((binomial(2*k,k)*Sum_{i=0..n-k}(binomial(k+1,n-k-i)*binomial(k+i,k)))/(k+1)^2)*(n+1).
Terms
- a(0) =1a(1) =5a(2) =14a(3) =45a(4) =164a(5) =662a(6) =2862a(7) =12957a(8) =60590a(9) =290218a(10) =1416216a(11) =7014714a(12) =35172968a(13) =178180968a(14) =910542696a(15) =4688140189a(16) =24296295636a(17) =126640986410a(18) =663465473910
External references
- oeis: A270661