[ exp(1/12)*n! ].

Terms

a(0) =1a(1) =2a(2) =6a(3) =26a(4) =130a(5) =782a(6) =5477a(7) =43823a(8) =394415a(9) =3944157a(10) =43385731a(11) =520628778a(12) =6768174123a(13) =94754437735