23291

Properties

Appears in sequences

• Primes that remain prime through 3 iterations of function f(x) = 9x + 4.at n=41A023297
• a(1)=1, a(2)=2; for n >= 2, a(n+1) = a(n) + sum of prime factors of a(n).at n=42A096461
• Primes p2 such that p1^2 + p2^3 is an average of twin primes and p1 < p2 are consecutive primes.at n=23A138716
• a(1) = 3. For n > 1, Ulam's spiral is started with a(n-1), and the primes p on the NE spoke are considered. a(n) is the minimal p that is the lesser of a twin prime pair.at n=30A163586
• 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=26A192896
• Primes p for which exactly four bases b with 1 < b < p exist such that p is a base b Wieferich prime.at n=39A255207
• a(0) = 2; for n>0, a(n) = smallest prime p such that p > a(n-1) and p is congruent to n modulo prime(n).at n=45A261192
• a(1)=3; for n>1, if n is odd a(n) = spf(Product_{k=1..n-1}(a(k))+1) else a(n) = spf(Product_{k=1..n-1}(a(k))-1), where spf is "smallest prime factor".at n=12A265009
• a(n) is the sum of the prime factors (with repetition) of the sum of the preceding terms; a(1)=a(2)=1.at n=43A268868
• a(n) is the sum of the prime factors, with repetition, of the sum of all preceding terms, with initial terms a(1)=1 and a(2)=2.at n=28A269004
• Records in A268868.at n=15A271927
• a(n) = A273059(4n).at n=27A275916
• a(n) = (n^3 + 9*n + 14*n + 9)/3.at n=41A322595
• G.f. A(x) satisfies A(x) = 1/((1 - x) * (1 - x*A(x) - x^6*A'''''(x))).at n=6A385761
• Prime numbersat n=2596