Genocchi numbers (of first kind); unsigned coefficients give expansion of x*tan(x/2).

A001469

Genocchi numbers (of first kind); unsigned coefficients give expansion of x*tan(x/2).

Terms

    a(0) =-1a(1) =1a(2) =-3a(3) =17a(4) =-155a(5) =2073a(6) =-38227a(7) =929569a(8) =-28820619a(9) =1109652905a(10) =-51943281731

External references