OFFSET
1,1
LINKS
Toshitaka Suzuki, Table of n, a(n) for n = 1..94
EXAMPLE
a(17) = 1777 is the smallest prime obtained by appending two 7s to 17.
MATHEMATICA
For[n = 1, n < 50, n++, If[n/7 <= Floor[n/7], k := 1; While[Not[PrimeQ[10^k*n + (10^k - 1)*7/9]], k++ ]; Print[10^k*n + (10^k - 1)*7/9]]] (* Stefan Steinerberger, Jan 27 2006 *)
Select[Table[First[Select[Rest[FromDigits/@Table[PadRight[{x}, n, 7], {n, 50}]], PrimeQ]], {x, 35}], NumberQ]//Quiet (* Harvey P. Dale, Jan 16 2011 *)
CROSSREFS
KEYWORD
sign,base
AUTHOR
Parthasarathy Nambi, Jan 03 2006
EXTENSIONS
More terms from Stefan Steinerberger, Jan 27 2006
Name and Data corrected by Toshitaka Suzuki, May 21 2023
STATUS
approved