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A082717 Plateau and depression primes of the form (10^a(n)-1)/9+8*(10^[ a(n)-1 ]+1) or (82*10^[ a(n)-1 ]+71)/9. 1
3, 247, 1141, 10395, 43881 (list; graph; refs; listen; history; internal format)
OFFSET

0,1

COMMENTS

Prime versus probable prime status and proofs are given in the author's table.

REFERENCES

C. Caldwell and H. Dubner, "Journal of Recreational Mathematics", Volume 28, No. 1, 1996-97, pp. 1-9.

LINKS

P. De Geest, PDP Reference Table

Makoto Kamada, Factorizations of 911...119.

EXAMPLE

a(n)=3 -> (10^3-1)/9+8*(10^2+1) = 919.

CROSSREFS

Cf. A082697 up to A082720.

Sequence in context: A092799 A140163 A157573 * A157777 A124875 A158351

Adjacent sequences:  A082714 A082715 A082716 * A082718 A082719 A082720

KEYWORD

nonn,base

AUTHOR

Patrick De Geest (pdg(AT)worldofnumbers.com), Apr 13 2003.

EXTENSIONS

One more term from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 02 2008

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Last modified February 16 11:51 EST 2012. Contains 205908 sequences.