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A057876 Primes p with the following property: let d_1, d_2, ... be the distinct digits occurring in the decimal expansion of p. Then for each d_i, dropping all the digits d_i from p produces a prime number.  Leading 0's are not allowed. 9
23, 37, 53, 73, 113, 131, 137, 151, 173, 179, 197, 211, 311, 317, 431, 617, 719, 1531, 1831, 1997, 2113, 2131, 2237, 2273, 2297, 2311, 2797, 3137, 3371, 4337, 4373, 4733, 4919, 6173, 7297, 7331, 7573, 7873, 8191, 8311, 8831, 8837, 12239, 16673, 19531 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Robert Israel, Table of n, a(n) for n = 1..1000

EXAMPLE

1531 gives primes 53, 131 and 151 after dropping digits 1, 5 and 3.

A larger example 1210778071 gives primes 12177871, 2077807, 110778071, 1210801 and 121077071 after dropping digits 0, 1, 2, 7 and 8.

MAPLE

filter:= proc(n) local L, d, Lp;

  if not isprime(n) then return false fi;

  L:= convert(n, base, 10);

  for d in convert(L, set) do

    Lp:= subs(d=NULL, L);

    if Lp=[] or Lp[-1] = 0 then return false fi;

    if not isprime(add(Lp[i]*10^(i-1), i=1..nops(Lp))) then return false fi;

  od;

  true

end proc:

select(filter, [seq(i, i=13..20000, 2)]); # Robert Israel, Jul 13 2018

CROSSREFS

Cf. A057877-A057883, A051362, A034302-A034305.

Sequence in context: A055114 A268343 A063643 * A244282 A051362 A034302

Adjacent sequences:  A057873 A057874 A057875 * A057877 A057878 A057879

KEYWORD

nonn,base

AUTHOR

Patrick De Geest, Oct 15 2000.

EXTENSIONS

Name edited by Robert Israel, Jul 13 2018

STATUS

approved

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Last modified July 21 22:02 EDT 2019. Contains 325210 sequences. (Running on oeis4.)