A089377 Numbers whose product of digits +1 and -1 gives twin prime pairs.

4, 6, 14, 16, 22, 23, 26, 29, 32, 34, 36, 41, 43, 56, 61, 62, 63, 65, 67, 76, 89, 92, 98, 114, 116, 122, 123, 126, 129, 132, 134, 136, 141, 143, 156, 161, 162, 163, 165, 167, 176, 189, 192, 198, 212, 213, 216, 219, 221, 223, 231, 232, 233, 235, 237, 249, 253, 256

Offset: 1

Author

Amarnath Murthy, Nov 08 2003

Keywords

• base
• nonn

Examples

			36 is a member since 3*6 = 18 and (17,19) is a twin prime pair.
		

Links

• Amiram Eldar, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A001097, A001359, A006512, A007954.

Programs

Mathematica

prodDig[n_] := Times @@ IntegerDigits[n]; Select[Range[256], And @@ PrimeQ [prodDig[#] + {-1, 1}] &] (* Amiram Eldar, Dec 27 2019 *)
Select[Range[300],AllTrue[Times@@IntegerDigits[#]+{1,-1},PrimeQ]&] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Jun 26 2021 *)

Extensions

More terms from David Wasserman, Sep 15 2005