a(n) = binomial coefficient C(2n, n-10).

Terms

a(0) =1a(1) =22a(2) =276a(3) =2600a(4) =20475a(5) =142506a(6) =906192a(7) =5379616a(8) =30260340a(9) =163011640a(10) =847660528a(11) =4280561376a(12) =21090682613a(13) =101766230790a(14) =482320623240