a(n) = Sum_{k=0..floor((n-3)/2)} T(n,k) * T(n,k+3), with T given by A026022.
A027297
a(n) = Sum_{k=0..floor((n-3)/2)} T(n,k) * T(n,k+3), with T given by A026022.
Terms
- a(0) =1a(1) =4a(2) =30a(3) =104a(4) =567a(5) =1952a(6) =9453a(7) =32900a(8) =150029a(9) =528956a(10) =2327156a(11) =8303216a(12) =35679835a(13) =128633440a(14) =543723257a(15) =1977821700a(16) =8260172309a(17) =30278441400a(18) =125314192728a(19) =462409521376
External references
- oeis: A027297