384858

Appears in sequences

• Partition the concatenation 1234567...of natural numbers into successive strings which are multiples of 9, all different and > 9. (0 never taken as the most significant digit.)at n=22A077302
• Numbers m such that tau(m) = 2 * tau(m - 1) and simultaneously sigma(m) = 2 * sigma(m - 1), where tau(k) = A000005(k) and sigma(k) = A000203(k).at n=6A353033