E.g.f.: exp(x+5/2*x^2).

Terms

a(0) =1a(1) =1a(2) =6a(3) =16a(4) =106a(5) =426a(6) =3076a(7) =15856a(8) =123516a(9) =757756a(10) =6315976a(11) =44203776a(12) =391582456a(13) =3043809016a(14) =28496668656a(15) =241563299776