2640625

Appears in sequences

• Smallest number that is the sum of 2 squares (allowing zeros) in exactly n ways.at n=10A000446
• Crystal ball sequence for D_4 lattice.at n=28A007204
• Smallest k such that circle x^2 + y^2 = k passes through exactly 4n integer points.at n=20A018782
• a(n) = n^2*(n-1)^3/4.at n=26A019584
• Squares that are a difference between 2 positive cubes.at n=25A038596
• Numbers of the form (5^i)*(13^j).at n=34A107466
• Smallest strictly positive number decomposable in n different ways as a sum of two squares.at n=10A124980
• Squares that remain squares when prefixed with a 9.at n=6A167044
• Number of (n+2)X(n+2) 0..1 arrays with no 3x3 subblock diagonal sum less than the antidiagonal sum or central row sum less than the central column sum.at n=25A258886
• Least perfect power that is the sum of two nonzero squares in exactly n ways.at n=9A273279
• Let n = p_1*p_2*...*p_k be the prime factorization of n, with the primes sorted in descending order. Then a(n) = 5^(p_1 - 1)*13^(p_2 - 1)*17^(p_3 - 1)*...*A002144(k)^(p_k - 1).at n=20A340388