A050716 Inserting a digit '6' between all adjacent digits of k makes a prime.
13, 17, 23, 29, 37, 41, 43, 47, 53, 59, 61, 71, 79, 83, 97, 101, 103, 107, 109, 127, 131, 133, 139, 151, 157, 161, 173, 193, 211, 221, 223, 227, 251, 269, 281, 283, 301, 307, 311, 323, 329, 347, 349, 353, 371, 377, 401, 421, 457, 463, 479, 481, 487, 517, 523
Offset: 1
Examples
481 becomes 4(6)8(6)1 becomes prime 46861.
Links
- Harvey P. Dale, Table of n, a(n) for n = 1..1001
Programs
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Mathematica
Select[Range[10,600],PrimeQ[FromDigits[Riffle[IntegerDigits[#],6]]]&] (* Harvey P. Dale, Aug 26 2013 *)
Extensions
Definition clarified by Harvey P. Dale, Aug 26 2013
Offset changed by Andrew Howroyd, Aug 14 2024