-1439038domain: ZAppears in sequencesA triangle sequence of polynomial coefficients: p(x,n)=(x - 1)^(3*n + 1)*Sum[(k*(k + 1)*(2*k + 1)/6)^n*x^k, {k, 0, Infinity}]/x.at n=19A154284A triangle sequence of polynomial coefficients: p(x,n)=(x - 1)^(3*n + 1)*Sum[(k*(k + 1)*(2*k + 1)/6)^n*x^k, {k, 0, Infinity}]/x.at n=21A154284