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A046258 a(1) = 8; a(n) is smallest number >= a(n-1) such that the juxtaposition a(1)a(2)...a(n) is a prime. 12
8, 9, 23, 51, 69, 81, 93, 129, 169, 179, 181, 273, 321, 321, 449, 639, 769, 857, 1047, 1213, 1233, 1443, 1587, 1637, 1953, 2433, 2599, 2639, 2901, 3261, 3681, 4059, 5109, 5169, 5407, 5691, 6149, 6531, 7939, 8081, 8211, 8439, 8589, 8623, 8663, 8757, 9459 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Robert Israel, Table of n, a(n) for n = 1..400

MAPLE

A[1]:= 8: A[2]:= 9: x:= 89:

for n from 3 to 100 do

  for y from A[n-1] by 2 do

    z:= x*10^(1+ilog10(y))+y;

    if isprime(z) then break fi;

  od:

  A[n]:= y;

  x:= z;

od:

seq(A[i], i=1..100); # Robert Israel, May 30 2018

MATHEMATICA

a[1] = 8; a[n_] := a[n] = Block[{k = a[n - 1], c = IntegerDigits @ Table[ a[i], {i, n - 1}]}, While[ !PrimeQ[ FromDigits @ Flatten @ Append[c, IntegerDigits[k]]], k ++ ]; k]; Table[ a[n], {n, 47}] (* Robert G. Wilson v, Aug 05 2005 *)

CROSSREFS

Cf. A069610, A074344, A033680, A033679, A033681, A046254, A046255, A046256, A046257, A046259, A111524.

Sequence in context: A322637 A322640 A303957 * A074344 A256932 A304600

Adjacent sequences:  A046255 A046256 A046257 * A046259 A046260 A046261

KEYWORD

nonn,base

AUTHOR

Patrick De Geest, May 15 1998

STATUS

approved

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Last modified September 29 14:10 EDT 2022. Contains 357090 sequences. (Running on oeis4.)