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A114784 Smallest prime of the form: all twos followed by prime(n). a(n) > prime(n). 0 if no such prime exists. 4
0, 23, 0, 227, 211, 2213, 22222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222217, 2222219, 223, 229, 2222222222222222222222222231, 2237, 241, 2243, 22247 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Prime(n) is all zeros followed by prime(n). This is all twos followed by prime(n). Conjecture: No term is zero except a(1) = a(3) = 0.

a(6) has not been proved prime, but it is a probable prime. - Joshua Zucker, May 06 2006

The 206-digit number 222...217 is, in fact, prime, as quickly confirmed by the Magma Calculator (http://magma.maths.usyd.edu.au/calc/). - Jon E. Schoenfield, Aug 24 2009

LINKS

Table of n, a(n) for n=1..15.

EXAMPLE

a(6) = 2213, as 213 is composite prime(6) = 13.

CROSSREFS

Cf. A114783.

Sequence in context: A143196 A092993 A238331 * A141517 A040534 A040533

Adjacent sequences:  A114781 A114782 A114783 * A114785 A114786 A114787

KEYWORD

base,nonn

AUTHOR

Amarnath Murthy, Nov 17 2005

EXTENSIONS

More terms from Joshua Zucker, May 06 2006

Edited by T. D. Noe, Oct 30 2008

STATUS

approved

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Last modified May 25 21:44 EDT 2022. Contains 354071 sequences. (Running on oeis4.)