a(n) = Sum_{k=0..n-2} T(n,k) * T(n,k+2), with T given by A026725.
A027209
a(n) = Sum_{k=0..n-2} T(n,k) * T(n,k+2), with T given by A026725.
Terms
- a(0) =1a(1) =7a(2) =34a(3) =173a(4) =741a(5) =3549a(6) =14670a(7) =68683a(8) =279715a(9) =1294598a(10) =5233060a(11) =24052965a(12) =96822587a(13) =442972139a(14) =1778697948a(15) =8110611295a(16) =32516501991a(17) =147897243768a(18) =592346459071
External references
- oeis: A027209