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A088647 a(1) = 1, then the smallest number such that the concatenation a(r), a(s) is prime for all s > r. 1
1, 1, 3, 7, 73, 433, 607, 13381, 37279, 4800307 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

Conjecture: sequence is finite.

LINKS

Table of n, a(n) for n=0..9.

EXAMPLE

a(5) = 73 as 173,373,773 are all prime.

CROSSREFS

Cf. A075611. [From R. J. Mathar, Sep 11 2008]

Sequence in context: A078552 A091259 A342546 * A075611 A191485 A119572

Adjacent sequences:  A088644 A088645 A088646 * A088648 A088649 A088650

KEYWORD

base,nonn

AUTHOR

Amarnath Murthy, Oct 29 2003

EXTENSIONS

More terms from David Wasserman, Aug 17 2005

STATUS

approved

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Last modified July 31 05:10 EDT 2021. Contains 346367 sequences. (Running on oeis4.)