27246198784domain: NAppears in sequencesCoefficients of Chebyshev polynomials: n*(2*n+1) * 4^(n-1).at n=13A002700a(n) = 2^(n-2)*binomial(n+1,2).at n=26A052482Sequence associated with a(n) = 2*a(n-1) + k*(k+2)*a(n-2).at n=27A080929