-875160domain: ZAppears in sequencesCoefficient of x^2 in 2n-th normalized Legendre polynomial.at n=7A100259Regular triangle, coefficients of the polynomial P(n)(x) = (-1)^(n+1)*(2*n+1)*binomial(2*n, n)*Sum_{i=0..n} x^i*binomial(n, i)/(n+i+1).at n=41A327809