a(n) = Sum_{k=0..n-2} T(n,k) * T(n,k+2), with T given by A026648.
A026973
a(n) = Sum_{k=0..n-2} T(n,k) * T(n,k+2), with T given by A026648.
Terms
- a(0) =1a(1) =8a(2) =52a(3) =224a(4) =1131a(5) =4620a(6) =23456a(7) =92752a(8) =460170a(9) =1805760a(10) =8946216a(11) =34942176a(12) =172593267a(13) =673129380a(14) =3323413216a(15) =12954246368a(16) =63944790462a(17) =249263001360
External references
- oeis: A026973