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A030468 Primes which when concatenated with next two primes are also prime. 2
5, 11, 17, 31, 41, 89, 229, 239, 263, 307, 313, 317, 353, 359, 383, 389, 401, 409, 439, 449, 563, 619, 701, 761, 773, 787, 797, 827, 907, 929, 1061, 1163, 1409, 1447, 1579, 1597, 1619, 1621, 1637, 1697, 1877, 1933, 2011, 2029, 2129, 2131 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Paolo P. Lava, Table of n, a(n) for n = 1..2500

EXAMPLE

concat(5, 7, 11) = 5711 is prime. - Paolo P. Lava, Jan 25 2017

MAPLE

with(numtheory): P:=proc(q) local a, b, c, d, n; for n from 1 to q do a:=ithprime(n); b:=nextprime(a); c:=nextprime(b); d:=b*10^(ilog10(c)+1)+c;

if isprime(a*10^(ilog10(d)+1)+d) then a; fi;

od; end: seq(P(k), k=1..400); # Paolo P. Lava, Jan 25 2017

CROSSREFS

Cf. A000040.

Sequence in context: A155882 A087373 A155030 * A277290 A085634 A157478

Adjacent sequences:  A030465 A030466 A030467 * A030469 A030470 A030471

KEYWORD

nonn,base

AUTHOR

Patrick De Geest

STATUS

approved

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Last modified June 25 20:26 EDT 2017. Contains 288730 sequences.