1326122
domain: N
Appears in sequences
- Second-order Euler numbers.at n=9A002435
- Triangle of coefficients in expansion of D^n (sec x) / sec x in powers of tan x.at n=31A008294
- Triangle T(n,k), 0 <= k <= n, read by rows, defined by T(0,0) = 1; T(0,k) = 0 if k>0 or if k<0; T(n,k) = k*T(n-1,k-1) + (k+1)*T(n-1,k+1).at n=57A104035
- Triangle read by rows: T(n,k) = value of (d^2n/dx^2n) (tan^(2k)(x)/cos(x)) at the point x = 0.at n=16A151775
- E.g.f.: sec(x)^2*tan(x)+sec(x)*tan(x)^2.at n=10A225689
- E.g.f. C(x,y) = cos(y) / sqrt(1 - sin(x)^2 - sin(y)^2).at n=22A324609
- E.g.f. C(y,x) = cos(x) / sqrt(1 - sin(x)^2 - sin(y)^2).at n=26A324611