E.g.f.: z*(((exp(z)+1)/((exp(z)+2*exp(-z/2)*cos(z*sqrt(3)/2))/3))-1).

A281586

E.g.f.: z*(((exp(z)+1)/((exp(z)+2*exp(-z/2)*cos(z*sqrt(3)/2))/3))-1).

Terms

    a(0) =0a(1) =1a(2) =2a(3) =3a(4) =-4a(5) =-15a(6) =-54a(7) =133a(8) =792a(9) =4293a(10) =-15130a(11) =-123849a(12) =-895212a(13) =4101799a(14) =42732522a(15) =386103915a(16) =-2177360656a(17) =-27544520691a(18) =-298649804706

External references