-4180

Appears in sequences

• Expansion of k/(4*q^(1/2)) in powers of q, where k defined by sqrt(k) = theta_2(0, q)/theta_3(0, q).at n=9A001938
• Expansion of log(1+tan(log(1+x))).at n=6A009363
• a(n) = 0^n + 1 - F(n-1)^2 - F(n)^2, where F = A000045.at n=10A186025
• Array: row n shows the coefficients of the characteristic polynomial of the n-th principal submatrix of (floor[(i+1)/2] if i=j and = 0 otherwise), as in A204162.at n=47A204163
• Alternating sum of 11-gonal (or hendecagonal) numbers.at n=43A266087
• a(n) = (-1)^n * A000045(n) + 1.at n=19A355020
• Expansion of g.f. A(x) satisfying A(x) = 2*x + A(2*x^2)^(1/2) with A(0) = 1.at n=18A371711