a(1) = 1; for n > 1, a(n) is the smallest unused positive number such that sopfr(|a(n) - a(n-1)|) = sopfr(a(n) + a(n-1)) and Omega(|a(n) - a(n-1)|) = Omega(a(n) + a(n-1)), where sopfr(k) is the sum of the primes dividing k, with repetition.

A370503

a(1) = 1; for n > 1, a(n) is the smallest unused positive number such that sopfr(|a(n) - a(n-1)|) = sopfr(a(n) + a(n-1)) and Omega(|a(n) - a(n-1)|) = Omega(a(n) + a(n-1)), where sopfr(k) is the sum of the primes dividing k, with repetition.