A158075 Prime numbers p such that (the largest digit of p) - (the smallest digit of p) is prime.

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

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)) then ithprime(n) end if end proc: seq(a(n), n = 1 .. 150); # 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 A347816

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