a(n) = (2/n)*Sum_{k=1..n} (2k+1)*M(k)^2 where M(k) is the Motzkin number A001006(k).

A295132

a(n) = (2/n)*Sum_{k=1..n} (2k+1)*M(k)^2 where M(k) is the Motzkin number A001006(k).

Terms

    a(0) =6a(1) =23a(2) =90a(3) =432a(4) =2286a(5) =13176a(6) =80418a(7) =513764a(8) =3400518a(9) =23167311a(10) =161640554a(11) =1150633512a(12) =8332048638a(13) =61232315553a(14) =455830692210

External references