A109357 Numbers k such that the string 112354k is prime.

1, 21, 73, 81, 127, 157, 159, 181, 211, 213, 217, 259, 267, 271, 273, 283, 289, 301, 303, 321, 327, 337, 369, 409, 423, 457, 477, 507, 523, 537, 553, 559, 597, 603, 621, 631, 651, 691, 699, 727, 799, 807, 817, 843, 849, 867, 877, 897, 909, 919, 927, 967, 969, 981, 993, 997, 1017, 1021, 1047

Offset

1,2

Links

Michael De Vlieger, Table of n, a(n) for n = 1..10000

Example

If k=1 then 112354k = 1123541 (prime).
If k=213 then 112354k = 112354213 (prime).

Mathematica

Select[Range[1050], PrimeQ[112354*10^IntegerLength[#] + #] &] (* Michael De Vlieger, Jan 22 2018 *)

Prog

(Magma) [ n: n in [1..1750] | IsPrime(Seqint(Intseq(n) cat [4, 5, 3, 2, 1, 1])) ]; // Vincenzo Librandi, Feb 02 2011

Crossrefs

Sequence in context: A156285 A160435 A240824 * A283802 A082041 A350160

Adjacent sequences: A109354 A109355 A109356 * A109358 A109359 A109360

Keyword

nonn,base

Author

Parthasarathy Nambi, Aug 22 2005

Extensions

More terms from Vincenzo Librandi, Feb 02 2011

Status

approved