a(n) = Sum_{k=0..floor(n/2)-2} T(n,k) * T(n,k+3), with T given by A026009.
A027290
a(n) = Sum_{k=0..floor(n/2)-2} T(n,k) * T(n,k+3), with T given by A026009.
Terms
- a(0) =3a(1) =9a(2) =73a(3) =230a(4) =1335a(5) =4376a(6) =22144a(7) =74766a(8) =351558a(9) =1213965a(10) =5458347a(11) =19181130a(12) =83735127a(13) =298391598a(14) =1276135088a(15) =4599546922a(16) =19380537318a(17) =70514368558a(18) =293838981413
External references
- oeis: A027290