81320

Appears in sequences

• Numbers n such that there are exactly 4 primes p such that floor(n*log(n))+1<=p<=floor((n+1)*log(n+1))-1.at n=28A068362
• a(n) = ((5+sqrt(2))*(4+sqrt(2))^n + (5-sqrt(2))*(4-sqrt(2))^n)/2.at n=6A162271
• Let s denote the sum of the abundant numbers in the aliquot parts of x. Sequence lists numbers x such that sigma(s) = usigma(x), where usigma(x) is the sum of the unitary divisors of x (A034448).at n=22A258135
• Larger of amicable pair m < n defined by t(n) = m and t(m) = n where t(n) = psi(n) - n and psi(n) = A001615(n) is the Dedekind psi function.at n=28A323330