7828053417

Appears in sequences

• Expansion of cos(x)/cos(2x).at n=6A000281
• Expansion of cos x (1 + sin x ) /cos 2x.at n=12A000825
• Generalized Euler numbers, or Springer numbers.at n=12A001586
• Expansion of e.g.f. exp(x)/cosh(2*x).at n=12A188458
• Expansion of e.g.f.: exp(-x) / cosh(2*x).at n=12A212435
• Shanks's array c_{a,n} (a >= 1, n >= 0) that generalizes Euler and class numbers, read by antidiagonals upwards.at n=34A235605
• a(n) = 4^n*Euler(n, 1/4)*2^(valuation_{2}(n + 1)).at n=12A339058