From an asymptotic expansion for Pi.

Terms

a(0) =1a(1) =1a(2) =1a(3) =-1a(4) =-5a(5) =23a(6) =53a(7) =-593a(8) =-5165a(9) =110123a(10) =231743a(11) =-8113223a(12) =-33497425a(13) =1744764499a(14) =3563384029a(15) =-258115578289