A092117 Numbers n such that the concatenation 2n3n5n7n11n13 is prime.

10, 43, 51, 55, 58, 60, 136, 171, 204, 213, 214, 222, 270, 288, 309, 334, 339, 364, 366, 376, 414, 423, 460, 477, 492, 501, 502, 507, 513, 519, 565, 585, 586, 597, 621, 649, 726, 729, 787, 852, 861, 870, 903, 906, 915, 933, 946, 981, 988, 1005, 1038, 1071

Offset: 1

Author

Farideh Firoozbakht, Jun 15 2003

Keywords

• nonn
• base

Comments

This concatenation is fp(6, n) as defined in A083677.

Examples

			10 is in the sequence because 210310510710111013 is prime.
		

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A032711, A083677, A083966, A083677, A092115, A083969.

Programs

Mathematica

v={};Do[If[PrimeQ[FromDigits[Join[{2}, IntegerDigits[n], {3}, IntegerDigits[n], {5}, IntegerDigits[n], {7}, IntegerDigits[n], {1, 1}, IntegerDigits[n], {1, 3}]]], v=Append[v, n]], {n, 1400}];v
fp6Q[n_] := PrimeQ[ FromDigits[ Flatten[ IntegerDigits /@ Insert[{2, 3, 5, 7, 11, 13}, n, {{2}, {3}, {4}, {5}, {6}}]]]]; Select[ Range[1100], fp6Q[ # ] &] (* Robert G. Wilson v, Dec 11 2004 *)
Select[Range[1100],PrimeQ[FromDigits[Flatten[IntegerDigits/@Riffle[{2,3,5,7,11,13}, #]]]]&] (* Harvey P. Dale, Mar 21 2013 *)

Extensions

Edited by N. J. A. Sloane at the suggestion of Andrew S. Plewe, May 27 2007