18658

Appears in sequences

• a(1) = 7; a(n+1) = a(n)-th nonprime, where nonprimes begin at 1.at n=37A025006
• a(1)=1, a(2)=2; for n >= 2, a(n+1) = a(n) + sum of prime factors of a(n).at n=38A096461
• Composite numbers k such that (Bell(k+1) - Bell(k)) mod k = 1.at n=6A179279
• a(n+1) is the sum of a(n) and the prime factors of a(n), counted with multiplicity. Start with a(0) = 3.at n=22A192896
• Numbers n such that n!3 + 3^3 is prime.at n=34A247886
• Numbers k such that sopfr(k) = tau(k)^3.at n=8A305349
• Expansion of g.f. Sum_{n>=1} q^n/(1-q^n-q^(3*n)).at n=27A368688
• Numbers whose second arithmetic derivative (A068346) is a primorial number (A002110) > 1.at n=26A368702
• a(n) = 3^n - 2^(n+1) - 1.at n=8A368956