28809

Appears in sequences

• Tricapped prism numbers.at n=26A005920
• Ruth-Aaron numbers (2): sum of prime divisors of n = sum of prime divisors of n+1 (both taken with multiplicity).at n=31A039752
• Larger of Smith brothers.at n=14A050220
• 9 times octagonal numbers: a(n) = 9*n*(3*n-2).at n=33A064201
• Numbers k such that sopfr(k) = sopf(k+1), where sopf(k) = A008472(k) and sopfr(k) = A001414(k).at n=21A064675
• Number of (w,x,y,z) with all terms in {1,...,n} and |x-y|=|y-z|.at n=27A212679
• Least positive integer k such that prime(prime(k)), prime(prime(k*n)), prime(p) and prime(q) form a 4-term arithmetic progression for some pair of primes p and q.at n=26A261462
• a(1) = 1; a(n+1) = -Sum_{d|n} d*a(d).at n=8A321384
• Two-column table read by rows: Primitive distinct pairs that have the same value of phi, sigma, and tau.at n=36A322688
• a(n) is the number of primes between (prime(n))^3 and (prime(n+1))^3.at n=43A365767