4444445

Appears in sequences

• Find smallest pair (x,y) such that x^2-y^2 = 11...1 (n times) = (10^n-1)/9; sequence gives value of y.at n=13A048612
• Smallest number k such that R(n) + k is a square, where R(n) = A002275.at n=13A083515
• Expansion of (1-6*x)/((1-x)*(1-10*x)).at n=7A093140