2102500

Appears in sequences

• Squares n with digit 1 that remain positive square after omitting all 1's from n.at n=25A176899
• Number of nX6 0..1 arrays avoiding 0 0 0 and 0 1 0 horizontally and 0 0 1 and 1 1 1 vertically.at n=10A207691
• a(n) = sigma_2(n)^2.at n=33A356533