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A081618
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Numbers n such that (product of first n primes)+1 is divisible by the (n+1)-th prime. Also n such that A075306(n)-1 is equal to A002110(n). Positions of 1 in A081617.
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1
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OFFSET
| 1,2
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COMMENTS
| a(5) is greater than 10^5.
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EXAMPLE
| The 8th prime, 19, divides 2*3*5*7*11*13*17+1=510511, thus 7 is a member.
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PROG
| (PARI) p=1:for(n=1, 10^5, p=p*prime(n): if((p+1)%prime(n+1)==0, print1(n", ")))
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CROSSREFS
| Sequence in context: A157693 A142116 A201955 * A160491 A120661 A185389
Adjacent sequences: A081615 A081616 A081617 * A081619 A081620 A081621
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KEYWORD
| nonn,hard,more
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AUTHOR
| Ralf Stephan (ralf(AT)ark.in-berlin.de), Mar 24 2003
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