-180224

Appears in sequences

• a(n+1)=2a(n)-4a(n-1)+4a(n-2).at n=22A035302
• 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=73A075615
• Array of coefficients in Zagier's polynomials P_(n,0)(x).at n=40A075733
• Coefficient table for Chebyshev polynomials T(2*n,x) (increasing even powers x, without zeros).at n=41A127674
• a(0)=1. a(n) = 2^(n-2)*(5-n), for n>0.at n=16A172160
• Coefficients in the expansion of 1/([r] + [2r]x + [3r]x^2 + ...); [ ] = floor, r = 9/5.at n=41A279781
• Coefficients of successive polynomials formed by iterating f(x) = -1 + 2x^2. Irregular triangle read by rows.at n=16A321369