OFFSET
1,1
COMMENTS
The next term is too big to include. - Sascha Kurz, Mar 19 2002
LINKS
Patrick De Geest, PDP Reference Table - 151.
Makoto Kamada, Prime numbers of the form 155...551.
EXAMPLE
11 is also a member in which a string of 0 5's is there between two one's.
MAPLE
a := 1:b := 5:i := 1:for n from 0 to 500 do c := a+10*(10^n-1)/9*b+10^(n+1)*a; if(isprime(c)) then d[i] := c; i := i+1; end if; end do:q := seq(d[j], j=1..i-1);
MATHEMATICA
Select[Table[FromDigits[Join[PadRight[{1}, n, 5], {1}]], {n, 500}], PrimeQ] (* Harvey P. Dale, Aug 08 2012 *)
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Amarnath Murthy, Feb 28 2002
EXTENSIONS
More terms from Sascha Kurz, Mar 19 2002
Edited by Ray Chandler, Nov 04 2014
STATUS
approved