388751domain: NAppears in sequencesDenominators of continued fraction convergents to sqrt(621).at n=9A042193a(n) = n^4 - 3*n^2 + 1.at n=25A057722Chebyshev polynomials S(n,25) with Diophantine property.at n=4A097780Number of twice-partitions of n into partitions with all odd lengths and sums.at n=29A358827