a(n) = Sum_{k=0..n-3} T(n,k) * T(n,k+3), with T given by A026725.
A027210
a(n) = Sum_{k=0..n-3} T(n,k) * T(n,k+3), with T given by A026725.
Terms
- a(0) =1a(1) =9a(2) =57a(3) =298a(4) =1545a(5) =7126a(6) =34603a(7) =151633a(8) =714481a(9) =3049328a(10) =14131926a(11) =59385159a(12) =272409611a(13) =1133433579a(14) =5163641033a(15) =21341122875a(16) =96751092786a(17) =397978832144
External references
- oeis: A027210