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A030996 Concatenation of n consecutive primes starting with the prime a(n) is a prime. 6
2, 2, 5, 2, 7, 113, 29, 107, 211, 691, 23, 11, 5, 71, 277, 181, 13, 307, 43, 223, 43, 167, 31, 23, 151, 29, 67, 383, 19, 53, 53, 277, 541, 37, 103, 127, 947, 79, 4409, 1699, 13, 73, 31, 107, 751, 1187, 1069, 859, 67, 229, 293, 47, 1303, 2909, 1319 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Paolo P. Lava, Table of n, a(n) for n = 1..250 (terms 1..100 from Zak Seidov)

MAPLE

with(numtheory): P:=proc(q) local a, b, j, k, n; for n from 1 to q do

for k from 1 to q do a:=ithprime(k); b:=a; j:=1; while j<n do j:=j+1; a:=a*10^(ilog10(nextprime(b))+1)+nextprime(b); b:=nextprime(b); od;

if isprime(a) then print(ithprime(k));

break; fi; od; od; end: P(10^4); # Paolo P. Lava, Jan 26 2017

CROSSREFS

Cf. A000040, A030997.

Sequence in context: A029603 A204202 A025124 * A309208 A293225 A305798

Adjacent sequences:  A030993 A030994 A030995 * A030997 A030998 A030999

KEYWORD

nonn,base

AUTHOR

Patrick De Geest, Warut Roonguthai

EXTENSIONS

Edited by Charles R Greathouse IV, Apr 30 2010

STATUS

approved

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Last modified November 18 02:02 EST 2019. Contains 329242 sequences. (Running on oeis4.)