82176836301domain: NAppears in sequencesCentral trinomial coefficients: largest coefficient of (1 + x + x^2)^n.at n=25A002426a(n) = A002426(n^2), where A002426 is the central trinomial coefficients.at n=5A225602a(n) = Sum_{k=0..n} binomial(2*k, k) * binomial(2*n+1, 2*k).at n=12A273055