a(n) = Sum_{k=0..n-3} T(n,k) * T(n,k+3), with T given by A026747.
A027226
a(n) = Sum_{k=0..n-3} T(n,k) * T(n,k+3), with T given by A026747.
Terms
- a(0) =1a(1) =11a(2) =75a(3) =496a(4) =2523a(5) =14903a(6) =68478a(7) =389040a(8) =1705001a(9) =9552071a(10) =40792260a(11) =227758442a(12) =957346363a(13) =5353798598a(14) =22267534284a(15) =125033595506a(16) =516148089100
External references
- oeis: A027226