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Search: id:A118949
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| A118949 |
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Numbers n such that 12345678901098765432*sum(k=1,n,10^(20k-19)) + 1 is prime. |
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+0
1
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OFFSET
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1,1
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COMMENT
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The first two terms are given in the linked source in "Table 42: Ten Types of 'Rare' Prime Numbers" for entry "C. Almost-equipandigital prime of the type: (12345678901098765432)n 1", which designates that 12345678901098765432 is concatenated n times and then 1 is appended. 337, found by PrimeForm using recurrence mode, corresponds to a 6741-digit probable prime. There are no other terms <= 3000.
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LINKS
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R. Ondrejka, The Top Ten: a Catalogue of Primal Configurations
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CROSSREFS
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Cf. A117390.
Adjacent sequences: A118946 A118947 A118948 this_sequence A118950 A118951 A118952
Sequence in context: A113561 A135538 A080809 this_sequence A053334 A001143 A138490
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KEYWORD
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bref,hard,more,nonn
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AUTHOR
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Rick L. Shepherd (rshepherd2(AT)hotmail.com), May 06 2006
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