306612

Appears in sequences

• Numbers n such that n divides the (left) concatenation of all numbers <= n written in base 7 (most significant digit on right).at n=15A061960
• Larger member of an infinitary amicable pair.at n=30A126170
• Larger of bi-unitary amicable pair.at n=31A292981
• Larger of tri-unitary amicable numbers pair: numbers (m, n) such that tsigma(m) = tsigma(n) = m + n, where tsigma(n) is the sum of the tri-unitary divisors of n (A324706).at n=21A324709