286025

Appears in sequences

• Numbers k that divide the (left) concatenation of all numbers <= k written in base 21 (most significant digit on left).at n=17A029490
• Numerators of continued fraction convergents to sqrt(523).at n=10A042000
• Fundamental nonnegative solution x(n) of the Diophantine equation x^2 - A045339(n)*y^2 = -2, for n >= 1.at n=26A339881