sec(tanh(x)+arctan(x))=1+4/2!*x^2+48/4!*x^4+1344/6!*x^6+71680/8!*x^8...

A013150

sec(tanh(x)+arctan(x))=1+4/2!*x^2+48/4!*x^4+1344/6!*x^6+71680/8!*x^8...

Terms

    a(0) =1a(1) =4a(2) =48a(3) =1344a(4) =71680a(5) =6134144a(6) =766639104a(7) =132845576192

External references