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A179025
Primes with a single 2 as the only prime digit.
2
2, 29, 211, 241, 269, 281, 421, 821, 829, 929, 1021, 1129, 1201, 1249, 1289, 1291, 1429, 1621, 2011, 2069, 2081, 2089, 2099, 2111, 2141, 2161, 2411, 2441, 2609, 2689, 2699, 2801, 2819, 2861, 2909, 2969, 2999, 4021, 4129, 4201, 4211, 4219, 4241, 4261
OFFSET
1,1
COMMENTS
This is a proper subsequence of A179024. - Jianing Song, Jul 10 2018
LINKS
MAPLE
Digs:= [0, 1, 2, 4, 6, 8, 9]:
f:= proc(n) local L, x;
L:= convert(n, base, 7);
if numboccur(2, L) <> 1 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
MATHEMATICA
Select[Prime[Range[600]], DigitCount[#, 10, 2]==1&&NoneTrue[ DeleteCases[ IntegerDigits[#], 2], PrimeQ]&] (* Harvey P. Dale, Feb 20 2022 *)
CROSSREFS
Cf. A179024.
Sequence in context: A342454 A009772 A179024 * A377627 A244599 A261268
KEYWORD
nonn,base
AUTHOR
Lekraj Beedassy, Jun 25 2010
EXTENSIONS
Terms confirmed by Ray Chandler, Jul 13 2010
Definition clarified by Harvey P. Dale, Feb 20 2022
STATUS
approved