OFFSET
1,1
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..1000
MATHEMATICA
f[n_]: = Block[{len = Floor[Log[10, n] + 1]}, Select[10^(7 + len) n + 10^len Table[k (10^7 - 1) / 9, {k, 9}] + n, PrimeQ@#&]]; Array[f, 1000]//Flatten
PROG
(Magma) m:=7; [p: d in [1..9], n in [1..80 by 2] | IsPrime(p) where p is n*(10^(m+t)+1)+d*10^t*(10^m-1) div 9 where t is #Intseq(n)]; //
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Vincenzo Librandi, Sep 12 2013
STATUS
approved