251008

Appears in sequences

• Expansion of cosh(x)/cos(sin(x)).at n=6A009181
• Expansion of exp(x)/cos(sin(x)).at n=12A009289
• a(n) = 3*a(n-1) - 2*a(n-2) - a(n-4) + a(n-5) with initial terms 1, 1, 1, 3, 6.at n=21A196787