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 A092967 Largest prime of the form a squarefree number + 1 where the prime divisors of the squarefree number are < n. 2
 2, 3, 7, 7, 31, 31, 211, 211, 211, 211, 2311, 2311, 6007, 6007, 6007, 6007, 102103, 102103, 3233231, 3233231, 3233231, 3233231, 17160991 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Conjecture: a(n)-1 has prime(n)-1 divisors. Subsidiary sequence: Number of primes of the form 2*p*q*r*...+1 where p, q, r, etc. are distinct odd primes < n. LINKS EXAMPLE a(13) = 6007 = 2*3*7*11*13 + 1, as 2*5*7*11*13 + 1, etc. are composite. MATHEMATICA <

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Last modified July 26 06:53 EDT 2021. Contains 346294 sequences. (Running on oeis4.)