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A158075 Prime numbers p such that the largest digit of p - the smallest digit of p is prime. 1
13, 29, 31, 41, 47, 53, 61, 79, 83, 97, 103, 107, 113, 131, 163, 181, 227, 229, 239, 241, 257, 269, 277, 281, 293, 307, 311, 313, 331, 353, 383, 421, 431, 449, 457, 461, 463, 467, 479, 499, 503, 523, 547, 557, 563, 577, 587, 607, 613, 631, 641, 643, 647, 653 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..1000

EXAMPLE

13 (3-1=2), 29 (9-2=7), 31 (3-1=2), 47 (7-4=3), 53 (5-3=2), etc.

MAPLE

a := proc (n) local nn, nnn: nn := convert(ithprime(n), base, 10): nnn := seq(nn[j], j = 1 .. nops(nn)): if isprime(max(nnn)-min(nnn)) = true then ithprime(n) else end if end proc: seq(a(n), n = 1 .. 150); [From Emeric Deutsch, Apr 01 2009]

MATHEMATICA

ldsdpQ[n_]:=Module[{idn=IntegerDigits[n]}, PrimeQ[Max[idn]-Min[idn]]]; Select[Prime[Range[200]], ldsdpQ] (* Harvey P. Dale, Jun 10 2013 *)

CROSSREFS

Sequence in context: A240819 A293661 A087593 * A087594 A320868 A319167

Adjacent sequences:  A158072 A158073 A158074 * A158076 A158077 A158078

KEYWORD

nonn,base,less

AUTHOR

Juri-Stepan Gerasimov, Mar 12 2009

EXTENSIONS

Missing terms (61,281,449,457,461,463,467,479,727,757,769) added by Emeric Deutsch, Apr 01 2009

STATUS

approved

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Last modified December 17 14:12 EST 2018. Contains 318201 sequences. (Running on oeis4.)