83904

Appears in sequences

• Composite numbers k such that phi(k) divides sigma(k) - 2*k.at n=29A068412
• a(1) = 1; a(n) = Sum_{k=1..n-1} phi(a(k)*a(n-k)), where phi(m) is the totient function.at n=17A105075
• Larger member of an infinitary amicable pair.at n=17A126170
• Infinitary amicable numbers.at n=36A127664
• G.f.: Product_{k>=1} (1 + x^(k^3)) / (1 - x^k).at n=40A280278
• 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=13A324709
• Numbers k such that sigma(k) = 2*k + 3*phi(k).at n=8A392691