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A117390 Numbers n such that 1234567890*sum(k=1,n,10^(10k-9)) + 1 is prime. 1
17, 56, 1888 (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 "B. Sequential prime of the type: (1234567890)n 1", which designates that 1234567890 is concatenated n times and then 1 is appended. 1888, found by PrimeForm using recurrence mode, corresponds to an 18881-digit probable prime. There are no other terms <= 3000.

LINKS

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

CROSSREFS

Sequence in context: A158968 A072895 A097059 * A141841 A146682 A146650

Adjacent sequences:  A117387 A117388 A117389 * A117391 A117392 A117393

KEYWORD

bref,hard,more,nonn

AUTHOR

Rick L. Shepherd (rshepherd2(AT)hotmail.com), May 03 2006

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Last modified February 14 18:47 EST 2012. Contains 205663 sequences.