-9408

Appears in sequences

• Let P(k,X) = Product_{i=1..2*k} (X-1/cos(Pi*(2*i-1)/(4*k)) ) which is a polynomial with integer coefficients. Sequence gives array of coefficients for P(k,X).at n=54A075615
• Array of coefficients in Zagier's polynomials P_(n,0)(x).at n=30A075733
• ( (Theta series of E_8)^(1/8) - (theta series of Leech lattice)^(1/24) ) / 30.at n=3A108772
• a(2n) = A001570(n), a(2n+1) = -A007654(n+1).at n=7A108946
• Series expansion of the elliptic function sqrt(k) = theta_2/theta_3 in powers of q^(1/4).at n=69A127391
• Expansion of the elliptic function sqrt(k(q))/q^(1/4) in powers of q, where sqrt(k(q)) = theta_2(q)/theta_3(q).at n=17A127392
• Expansion of 8 * eta(q)^7 / eta(q^7) + 49 * (eta(q) * eta(q^7))^3 in powers of q.at n=39A138809
• Let c(n) = x^(2^n-1)*(1-x^(2^n)), g(n) = 1 + x^(2^n-1) + x^(2^n), h(n) = Product_{i=1..n} g(i); then use g.f. (1+2*x) - Sum_{n>=1} c(n)/h(n).at n=64A151684
• Expansion of phi(q) / phi(q^4) in powers of q where phi() is a Ramanujan theta function.at n=69A208274
• Expansion of phi(x) / phi(x^2) * f(-x, -x^7) / f(-x^3, -x^5) in powers of x where phi(), f() are Ramanujan theta functions.at n=34A230534
• Expansion of (phi(x) / phi(x^2)) * (f(-x^3, -x^5) / f(-x^1, -x^7)) in powers of x where phi(), f() are Ramanujan theta functions.at n=35A245434