A179024 Primes whose only prime digits are 2's.

2, 29, 211, 229, 241, 269, 281, 421, 821, 829, 929, 1021, 1129, 1201, 1229, 1249, 1289, 1291, 1429, 1621, 2011, 2029, 2069, 2081, 2089, 2099, 2111, 2129, 2141, 2161, 2221, 2269, 2281, 2411, 2441, 2609, 2621, 2689, 2699, 2801, 2819, 2861, 2909, 2969, 2999

Offset

1,1

Comments

At least one digit 2 is required. - Robert Israel, Jul 10 2018

A179025 is a proper subsequence. - Jianing Song, Jul 10 2018

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Maple

Digs:= [0, 1, 2, 4, 6, 8, 9]:
f:= proc(n) local L, x;
  L:= convert(n, base, 7);
  if not member(2, L) then return NULL fi;
  x:= add(Digs[L[i]+1]*10^(i-1), i=1..nops(L));
  if isprime(x) then x fi
end proc:
map(f, [$1..2000]); # Robert Israel, Jul 10 2018

Crossrefs

Cf. A179025.

Sequence in context: A369384 A342454 A009772 * A179025 A244599 A261268

Adjacent sequences: A179021 A179022 A179023 * A179025 A179026 A179027

Keyword

nonn,base

Author

Lekraj Beedassy, Jun 25 2010

Extensions

Corrected by Ray Chandler, Jul 13 2010

Status

approved