51733504

Appears in sequences

• Expansion of e.g.f. (1 + tan(x))/(1 - tan(x)).at n=10A000831
• E.g.f.: Sum_{n >= 0} a(n)*x^(2*n)/(2*n)! = sec(2*x).at n=5A002436
• Expansion of e.g.f. log(1 + tan(x)).at n=11A003707
• Triangle related to exp(x)*sec(2*x).at n=55A117436
• Exponential Riordan array [sec(2x), arctanh(tan(x))].at n=55A166317
• Square array A(n,k), n>=0, k>=0, read by antidiagonals, where column k is the expansion of continued fraction 1/(1 - 2^k*x/(1 - 4^k*x/(1 - 6^k*x/(1 - 8^k*x/(1 - 10^k*x/(1 - ...)))))).at n=33A291260
• Irregular triangle read by rows: coefficients of q-Eulerian polynomials of Type B.at n=34A333273
• Triangle read by rows: T(n, k) = (-1)^(n-k) * (2*n + 1)! * [y^(2*k)] [x^(2*n+1)] arctan(sec(x*y)*tanh(x)).at n=15A371687