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A118949 Numbers n such that 12345678901098765432*sum(k=1,n,10^(20k-19)) + 1 is prime. 0
6, 16, 337 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

COMMENTS

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.

LINKS

R. Ondrejka, The Top Ten: a Catalogue of Primal Configurations

CROSSREFS

Cf. A117390.

Sequence in context: A152663 A113561 A080809 * A053334 A001143 A177365

Adjacent sequences:  A118946 A118947 A118948 * A118950 A118951 A118952

KEYWORD

bref,hard,more,nonn

AUTHOR

Rick L. Shepherd (rshepherd2(AT)hotmail.com), May 06 2006

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Last modified February 17 13:10 EST 2012. Contains 206030 sequences.