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A261033
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Values of n such that A002110(n) - A007504(n) - 1 is a prime number.
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0
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OFFSET
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1,1
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COMMENTS
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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.
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LINKS
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Table of n, a(n) for n=1..5.
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EXAMPLE
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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.
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PROG
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(PARI) for(n=1, 1e5, if(ispseudoprime(prod(k=1, n, prime(k)) - sum(k=1, n, prime(k)) - 1), print1(n, ", ")));
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CROSSREFS
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Cf. A002110, A007504, A008578, A014284.
Sequence in context: A349828 A096231 A100432 * A145341 A121388 A161700
Adjacent sequences: A261030 A261031 A261032 * A261034 A261035 A261036
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KEYWORD
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nonn,more
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AUTHOR
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Altug Alkan, Nov 18 2015
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STATUS
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approved
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