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A038370
Smallest prime with "n^2" as central digit(s).
1
101, 113, 149, 191, 1163, 1259, 1361, 1493, 2647, 1811, 11003, 11213, 11443, 11699, 11969, 12251, 12569, 12893, 13241, 13613, 14009, 14411, 14843, 15299, 15761, 16253, 16763, 17291, 27847, 18413, 19001, 29611, 210241, 110899, 311561, 112253, 112967
OFFSET
0,1
COMMENTS
See also A084413, A084414.
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
Sequence in context: A084414 A164937 A105992 * A084430 A182693 A328996
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