21613201

Appears in sequences

• a(n) = the n-th divisor of r(n)^n, where r(n) = (10^n-1)/9 the repunits and the positive divisors of r(n)^n are written in order from smallest to largest.at n=6A121154
• Expansion of x*(1+2*x)/((1-2*x)*(1-x+4*x^2)).at n=24A335840