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A090510 a(n) is the least prime beginning with prime(n) such that the concatenation a(1)a(2)...a(n) is a prime. 2
2, 3, 509, 79, 1163, 13033, 1721, 19, 233, 29569, 3119, 37057, 410171, 43003, 47111, 5323, 59219, 61291, 670223, 710911, 73331, 795793, 83399, 894709, 975581, 101383, 1033079, 1071937, 109073, 1130257, 1276397, 1313911, 1378673, 1395469, 1491233 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Robert Israel, Table of n, a(n) for n = 1..461

MAPLE

dcat:= proc(a, b) 10^(1+ilog10(b))*a+b end proc:

S:= 2: R:= 2:

for n from 2 to 35 do

  found:= false;

  for d from 0 while not found do

     cand:= 10^d*ithprime(n)-1;

     do

       cand:= nextprime(cand);

       if cand >= 10^d*(ithprime(n)+1) then break fi;

       Sc:= dcat(S, cand);

       if isprime(Sc) then found:= true; break fi

   od od;

   R:= R, cand;

   S:= Sc;

od:

R; # Robert Israel, Aug 06 2020

CROSSREFS

Cf. A090511.

Sequence in context: A128874 A196070 A173342 * A348360 A004887 A240709

Adjacent sequences:  A090507 A090508 A090509 * A090511 A090512 A090513

KEYWORD

base,nonn

AUTHOR

Amarnath Murthy, Dec 06 2003

EXTENSIONS

More terms from Max Alekseyev, Feb 08 2010

STATUS

approved

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Last modified October 26 08:00 EDT 2021. Contains 348267 sequences. (Running on oeis4.)