69641domain: NAppears in sequencesNumbers k such that k and k^2 use only the digits 1, 4, 6, 8 and 9.at n=20A137055Coefficient array for powers of x^2 of polynomials appearing in a generalized Melham conjecture on alternating sums of fifth powers of Chebyshev S polynomials with odd indices.at n=45A220671