11184128

Appears in sequences

• Triangle of tangent numbers.at n=36A008308
• Expansion of e.g.f.: cosh(log(1+sin(x))).at n=12A009123
• E.g.f. (1/2) * tan(x)^2 (even powers only).at n=6A024283
• Triangle T(n,k) (n >= 1, 0 <= k <= floor((n-1)/2)) read by rows, where T(n,k) = (k+1)T(n-1,k) + (2n-4k)T(n-1,k-1).at n=41A101280
• E.g.f.: sec(x)^3+(sec(x)^2*tan(x)).at n=11A225688
• E.g.f.: sec(x)^2*tan(x)+sec(x)*tan(x)^2.at n=11A225689
• Triangle read by rows, whose row sums using Euler numbers are the unsigned even-indexed Bernoulli numbers (denominators).at n=24A229097
• Related to Euler numbers, expansion of e.g.f. tan(x)^2.at n=10A259688
• E.g.f.: C(x,k) = 1 + Integral S(x,k)*D(x,k)^2 dx, such that C(x,k)^2 - S(x,k)^2 = 1, and D(x,k)^2 - k^2*S(x,k)^2 = 1, as a triangle of coefficients read by rows.at n=26A322231
• E.g.f. S(x,y) = sin(x) / sqrt(1 - sin(x)^2 - sin(y)^2).at n=22A324610
• E.g.f. S(y,x) = sin(y) / sqrt(1 - sin(x)^2 - sin(y)^2).at n=26A324612
• E.g.f.: D(x,k) = dn( i * Integral C(x,k) dx, k) such that C(x,k) = cn( i * Integral C(x,k) dx, k), where D(x,k) = Sum_{n>=0} Sum_{j=0..n} T(n,j) * x^(2*n)*k^(2*j)/(2*n)!, as a triangle of coefficients T(n,j) read by rows.at n=22A325222
• Number of n-bead necklace structures which are not self-equivalent under a nonzero rotation using a maximum of four different colored beads.at n=16A328743
• a(n) = numerator (2^(4*n-1) * (2^(4*n-2) - 1) * (Bernoulli(4*n-2) / (4*n-2)!) * ((2*n-2)! / Euler(2*n-2))^2).at n=3A334912
• a(n) = Sum_{k=0..n-2} A205497(n, k) * (1 - k mod 2) if n >= 2, a(0) = a(1) = 1.at n=13A373752
• a(n) = Sum_{k=0..n-2} A205497(n, k) * (k mod 2).at n=13A373753