71604

Appears in sequences

• a(n) = T(3n,n), where T is the array defined in A025564.at n=6A025571
• Partial sums of A051797.at n=14A051878
• Numbers k such that phi(k) and sigma(k) are both perfect squares.at n=22A067781
• a(n) = 13 + floor(Sum_{j=1..n-1} a(j)/3).at n=30A120157
• Lower Pythagorean twins.at n=28A228876
• Number of nX2 nonnegative integer arrays with upper left 0 and lower right n+2-5 and value increasing by 0 or 1 with every step right or down.at n=16A252970
• First elements of maximal isospectral chains of length 3.at n=8A335082
• The number of edges on a 2 by 1 ellipse formed by the straight line segments mutually connecting all points formed by dividing the ellipse into 2n equal angle sectors from its origin.at n=15A341764