H_n(-1/2), where H_n(x) is Hermite polynomial of degree n.

Terms

a(0) =1a(1) =-1a(2) =-1a(3) =5a(4) =1a(5) =-41a(6) =31a(7) =461a(8) =-895a(9) =-6481a(10) =22591a(11) =107029a(12) =-604031a(13) =-1964665a(14) =17669471a(15) =37341149a(16) =-567425279a(17) =-627491489a(18) =19919950975a(19) =2669742629a(20) =-759627879679a(21) =652838174519