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A066725 Primes p the product of whose digits increased by one is prime. 3
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 (list; graph; refs; listen; history; text; internal format)
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

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Last modified July 8 07:16 EDT 2020. Contains 335513 sequences. (Running on oeis4.)