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A241212 Primes p with an even number of digits such that each digit in the second half of p is larger by 1 than the corresponding digit in the first half. 1
23, 67, 89, 1021, 1223, 1627, 3041, 4051, 4253, 4657, 5869, 7283, 7687, 8293, 106217, 110221, 112223, 128239, 130241, 136247, 158269, 172283, 178289, 188299, 208319, 226337, 230341, 250361, 272383, 286397, 320431, 322433, 326437, 328439, 338449, 340451 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Robert Israel, Table of n, a(n) for n = 1..10000

EXAMPLE

E.g., for 2 digit primes: (3, 7, 9) = (2, 6, 8) + 1.

MAPLE

N:= 1000; # to get the first N entries

A241212[1]:= 23:

A241212[2]:= 67:

A241212[3]:= 89:

count:= 3:

for n from 2 while count < N do

  for x1 from 10^(n-1) to 9*10^(n-1)-2 by 2 while count < N do

    L:= convert(x1, base, 10);

    if has(L, 9) then next fi;

    x:= 10^n*x1 + x1 + (10^n - 1)/9;

    if isprime(x) then

      count:= count+1;

      A241212[count]:= x

    fi;

  od

od: # Robert Israel, Apr 18 2014

CROSSREFS

Sequence in context: A141849 A125873 A059241 * A052087 A030458 A053559

Adjacent sequences:  A241209 A241210 A241211 * A241213 A241214 A241215

KEYWORD

nonn,base

AUTHOR

Zak Seidov, Apr 17 2014

EXTENSIONS

Incorrect cross-reference deleted by Robert Israel, Apr 18 2014

STATUS

approved

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Last modified May 25 11:17 EDT 2019. Contains 323539 sequences. (Running on oeis4.)