A066725 Primes p the product of whose digits increased by one is prime.

2, 11, 23, 29, 41, 43, 47, 61, 67, 89, 149, 163, 167, 211, 223, 227, 229, 233, 251, 257, 263, 269, 281, 349, 367, 383, 419, 431, 433, 439, 463, 491, 521, 523, 569, 587, 613, 617, 631, 643, 659, 661, 673, 761, 769, 821, 827, 857, 883, 887, 929, 941, 967, 1123

Offset

1,1

Links

Harry J. Smith, Table of n, a(n) for n = 1..1000

Formula

A084354 MINUS A011540. - R. J. Mathar, Aug 26 2007

Example

2 * 2 * 3 + 1 = 13, a prime; since 223 is also prime, it is a term of the sequence.

Mathematica

Select[Prime[Range[200]], PrimeQ[Times@@IntegerDigits[#]+1]&] (* Harvey P. Dale, May 09 2012 *)

Prog

(PARI) ProdD(x)= { local(p=1); while (x>9 && p>0, p*=x%10; x\=10); return(p*x) } { n=0; for (m=1, 10^10, if (isprime(ProdD(p=prime(m)) + 1), write("b066725.txt", n++, " ", p); if (n==1000, return)) ) } \\ Harry J. Smith, Mar 19 2010

Crossrefs

Sequence in context: A001032 A045386 A084354 * A087340 A246622 A237813

Adjacent sequences: A066722 A066723 A066724 * A066726 A066727 A066728

Keyword

easy,nonn,base

Author

Joseph L. Pe, Jan 15 2002

Extensions

Terms a(35) - a(54) from Harry J. Smith, Mar 19 2010

Status

approved