1773584640domain: NAppears in sequencesNumbers k for which sigma(k)/k - 8/9 is an integer.at n=9A218418Numbers k for which k * gcd(sigma(k), A003961(k)) is equal to sigma(k) * gcd(k, A003961(k)), where A003961 shifts the prime factorization one step towards larger primes, and sigma is the sum of divisors function.at n=28A349745