

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
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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^(n1) to 9*10^(n1)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 crossreference deleted by Robert Israel, Apr 18 2014


STATUS

approved



