[VA] Short & Sweet Math Challenge #24: "2019 Spring Special 5-tier"

[Albert Chan]

Calculate cin(x) taylor coefficients with XCas. Only need adjust vars for more terms.

vars := [a3, a5, a7, a9, a11, a13, a15];

n := 2*len(vars) + 1;
y := x + sum(vars(k) * x^(2*k+1), k, 1, (n-1)/2);
cin(x0) := subst(y, x=x0);

solve(coeff( taylor(cin(taylor(cin(cin(x)), x, n)) - sin(x), x, n, polynom), x) = 0, vars)
→ [-1/18, -7/1080, -643/408240, -13583/29393280 ...]