A020470 Primes that contain digits 7 and 8 only.

7, 787, 877, 887, 7877, 8887, 78787, 78877, 78887, 87877, 87887, 777787, 777877, 778777, 787777, 878777, 888887, 7778777, 7788787, 7877777, 7878877, 7878887, 7888877, 8787887, 8788777, 8877787, 8887777, 77778887, 77787887, 77877887

Offset: 1

Author

David W. Wilson

Keywords

• nonn
• base

Links

• Jason Bard, Table of n, a(n) for n = 1..10000 (first 1000 terms from Vincenzo Librandi)

Programs

Magma

[p: p in PrimesUpTo(77877887) | Set(Intseq(p)) subset [7,8]]; // Vincenzo Librandi, Jul 28 2012

Mathematica

Flatten[Table[Select[FromDigits/@Tuples[{7,8},n],PrimeQ],{n,8}]] (* Vincenzo Librandi, Jul 28 2012 *)