E.g.f. exp( 1 - x - sqrt( 1 - 4*x + x^2 )).

A078634

E.g.f. exp( 1 - x - sqrt( 1 - 4*x + x^2 )).

Terms

    a(0) =1a(1) =1a(2) =4a(3) =28a(4) =289a(5) =3991a(6) =69391a(7) =1458199a(8) =35976298a(9) =1019869624a(10) =32674379941

External references