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 A261033 Values of n such that A002110(n) - A007504(n) - 1 is a prime number. 0
 3, 5, 7, 9, 13 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Values of n such that difference between product of first n+1 terms of A008578 and sum of first n+1 terms of A008578 is a prime number. Initial primes of the form A002110(n) - A007504(n) - 1 are 19, 2281, 510451. LINKS EXAMPLE a(1) = 3 because (2*3*5) - (2+3+5) - 1 = 19 is prime. a(2) = 5 because (2*3*5*7*11) - (2+3+5+7+11) - 1 = 2281 is prime. a(3) = 7 because (2*3*5*7*11*13*17) - (2+3+5+7+11+13+17) - 1 = 510451 is prime. PROG (PARI) for(n=1, 1e5, if(ispseudoprime(prod(k=1, n, prime(k)) - sum(k=1, n, prime(k)) - 1), print1(n, ", "))); CROSSREFS Cf. A002110, A007504, A008578, A014284. Sequence in context: A349828 A096231 A100432 * A145341 A121388 A161700 Adjacent sequences: A261030 A261031 A261032 * A261034 A261035 A261036 KEYWORD nonn,more AUTHOR Altug Alkan, Nov 18 2015 STATUS approved

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Last modified March 27 03:44 EDT 2023. Contains 361553 sequences. (Running on oeis4.)