A103758 Numbers n such that the string 100n is the decimal expansion of a prime number.

9, 37, 39, 61, 67, 69, 79, 91, 93, 99, 103, 109, 129, 151, 153, 169, 183, 189, 193, 207, 213, 237, 267, 271, 279, 291, 297, 313, 333, 343, 357, 361, 363, 379, 391, 393, 403, 411, 417, 447, 459, 469, 483, 493, 501, 511, 517, 519, 523, 537, 547, 549, 559, 591

Offset

1,1

Comments

n such that n + 10^(2+A055642(n)) is prime. - Robert Israel, Feb 23 2016

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Example

9 is in the sequence because 1009 is prime.
99 is in the sequence because 10099 is prime.
103 is in the sequence because 100103 is prime.

Maple

select(n -> isprime(n + 10^(3+ilog10(n))), [$1..10^3]); # Robert Israel, Feb 23 2016

Mathematica

Select[Range[600], PrimeQ[FromDigits[Join[{1, 0, 0}, IntegerDigits[#]]]]&] (* Harvey P. Dale, Sep 02 2020 *)

Prog

(Magma) [ n: n in [1..700] | IsPrime(Seqint(Intseq(n) cat [0, 0, 1])) ];
(Magma) [n: n in [1..600] | IsPrime(n+10^(2+#Intseq(n)))]; // Vincenzo Librandi, Feb 24 2016
(PARI) isok(n) = isprime(eval(concat(Str(100), Str(n)))); \\ Michel Marcus, Feb 23 2016

Crossrefs

Cf. A103603, A103602, A103601.

Sequence in context: A116108 A232257 A091961 * A274769 A126914 A337238

Adjacent sequences: A103755 A103756 A103757 * A103759 A103760 A103761

Keyword

base,nonn

Author

Parthasarathy Nambi, Mar 28 2005

Extensions

More terms from Vincenzo Librandi, Feb 01 2011

Status

approved