OFFSET
0,1
COMMENTS
1195 is the smallest n such that 2 digits are needed on both sides of 1195^2 = 1428025 to give prime 10142802503. - Michel Marcus, Jun 05 2013
PROG
(PARI) a(n) = {a = 1; ok = 0; while (!ok, lena = #Str(a); lenn = #Str(n^2); for (b=0, 10^lena - 1, p = b + 10^lena*n^2 + 10^(lenn+lena)*a; if (isprime(p), return (p)); ); a++; ); } \\ Michel Marcus, Jun 05 2013
CROSSREFS
KEYWORD
easy,nonn,base
AUTHOR
Zak Seidov, Jun 25 2003
EXTENSIONS
Corrected by Robert G. Wilson v, Jun 27 2003
a(19) corrected by Sean A. Irvine, Jan 12 2021
STATUS
approved