607920

Appears in sequences

• Numbers n such that 77*2^n-1 is prime.at n=29A050564
• Lesser of semi-unitary amicable numbers pair: numbers (m, n) such that susigma(m) = susigma(n) = m + n, where susigma(n) is the sum of the semi-unitary divisors of n (A322485).at n=34A322541
• E.g.f. A(x) satisfies A'(x) = 1 - 2 * log(1-x) * A(x).at n=10A355231