69492

Appears in sequences

• Numbers n such that n divides the (right) concatenation of all numbers <= n written in base 10 (most significant digit on right).at n=22A029503
• G.f. = b(2)*b(6)/(x^6-x^4+x^2-2*x+1), where b(k) = (1-x^k)/(1-x).at n=23A266336
• For n >= 1, a(n) is the least k >= 0 such that k^2 + k + 1 is divisible by 2^n - 1 or a(n) = -1 if no such k exists.at n=18A372494