231881

Appears in sequences

• Positive numbers y such that y^2 is of the form x^2+(x+409)^2 with integer x.at n=12A160577
• Number of (n+2) X 4 0..2 arrays with every 3 X 3 subblock commuting with each horizontal and vertical neighbor 3 X 3 subblock.at n=16A186561
• a(n) is the start of the least run of exactly n consecutive positive numbers with strictly decreasing values of A177329, or -1 if no such run exists.at n=8A374674