A166565 Primes p such that product of digits +- 1 is prime.

23, 29, 41, 43, 61, 67, 89, 163, 167, 223, 233, 269, 349, 383, 431, 439, 463, 523, 569, 613, 617, 631, 643, 659, 761, 883, 1123, 1129, 1163, 1213, 1223, 1231, 1237, 1249, 1291, 1321, 1327, 1361, 1429, 1439, 1453, 1459, 1493, 1523, 1543, 1549, 1613, 1621

Offset

1,1

Comments

23 is in sequence because 2*3+1=7 and 2*3-1=5; 41 because 4*1+1=5 and 4*1-1=3.

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Mathematica

Select[Prime[Range[5000]], PrimeQ[Times@@IntegerDigits[#] - 1] && PrimeQ[Times@@IntegerDigits[#] + 1] &] (* Vincenzo Librandi, Feb 15 2014 *)

Crossrefs

Sequence in context: A225319 A228139 A094383 * A050207 A162658 A303009

Adjacent sequences: A166562 A166563 A166564 * A166566 A166567 A166568

Keyword

nonn,base

Author

Vincenzo Librandi, Oct 28 2009

Extensions

Corrected (29 inserted) and extended beyond 659 by R. J. Mathar, Nov 30 2009

Status

approved