Related to Euler numbers, expansion of e.g.f. tan(x)^2.

A259688

Related to Euler numbers, expansion of e.g.f. tan(x)^2.

Terms

    a(0) =1a(1) =2a(2) =8a(3) =16a(4) =136a(5) =272a(6) =3968a(7) =7936a(8) =176896a(9) =353792a(10) =11184128a(11) =22368256a(12) =951878656a(13) =1903757312a(14) =104932671488a(15) =209865342976

External references