408360

Appears in sequences

• Second-order Euler numbers.at n=8A002435
• Triangle of coefficients in expansion of D^n (sec x) / sec x in powers of tan x.at n=26A008294
• 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=48A104035
• Triangle T(n,k) (n>=0, 0<=k<=n) read by rows: T(0,0)=T(1,1)=1; T(n,0) is the Euler number A000111(n-1) for n>=1; T(n,n-1) = T(n,n) = (n-2)! for n>=2; interior entries are given by T(n,k) = m*T(n-1,k-1)+(k+1)*T(n-1,k+1) where m = k if n+k is even or k-1 if n+k is odd.at n=58A350970
• Expansion of e.g.f.: (sec(x)*tan(x))^2*(1+sin(x)).at n=9A350971
• T(n,n-7), where T(*,*) is A350970.at n=3A350974