E.g.f.: exp(x+x^2/2!+x^3/3!)/(1-x).

A130908

E.g.f.: exp(x+x^2/2!+x^3/3!)/(1-x).

Terms

    a(0) =1a(1) =2a(2) =6a(3) =23a(4) =106a(5) =576a(6) =3622a(7) =26006a(8) =210828a(9) =1910096a(10) =19162096a(11) =211095732a(12) =2534829376a(13) =32962249568a(14) =461527198056

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