|
|
A108829
|
|
Primes such that the outer 2 digits are n and n-1 and all inner digits are 1, where 0 < n < 9.
|
|
0
|
|
|
211, 2111, 8117, 41113, 411113, 8111111117, 2111111111111, 41111111111113, 811111111111111117, 2111111111111111111, 211111111111111111111111, 41111111111111111111111111111113, 41111111111111111111111111111111111111111111111111111113
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
LINKS
|
|
|
MATHEMATICA
|
Sort[Select[Flatten[Table[FromDigits[Join[{n}, PadRight[{}, i, 1], {n-1}]], {n, 2, 8}, {i, 60}]], PrimeQ]] (* Harvey P. Dale, Mar 06 2014 *)
|
|
PROG
|
(PARI) n10np1(n, d) = { local(x, y, k); for(x=1, n, for(k=1, 8, y=10^(x+1)*k+floor(10^x*d/9)*10+k-1; if(isprime(y), print1(y", ")) ) ) }
|
|
CROSSREFS
|
|
|
KEYWORD
|
easy,nonn,base
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|