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A058375
Palindromic primes with just two distinct prime digits.
0
353, 373, 727, 757, 32323, 33533, 35353, 72227, 72727, 75557, 77377, 3222223, 3223223, 3233323, 3337333, 3353533, 3553553, 3773773, 7722277, 7733377, 7772777, 322222223, 322323223, 323222323, 323232323, 323333323, 333535333
OFFSET
1,1
MATHEMATICA
Select[ Range[ 1, 780000000, 2 ], PrimeQ[ # ] && Length[ Union[ IntegerDigits[ # ] ] ] == 2 && IntegerDigits[ # ] == Reverse[ IntegerDigits[ # ] ] && Position[ IntegerDigits[ # ], 0 ] == {} && Position[ IntegerDigits[ # ], 1 ] == {} && Position[ IntegerDigits[ # ], 4 ] == {} && Position[ IntegerDigits[ # ], 6 ] == {} && Position[ IntegerDigits[ # ], 8 ] == {} && Position[ IntegerDigits[ # ], 9 ] == {} & ]
Select[Prime[Range[18*10^6]], PalindromeQ[#]&&AllTrue[ IntegerDigits[ #], PrimeQ] && Length[ Union[ IntegerDigits[ #]]] ==2&] (* Harvey P. Dale, Dec 16 2021 *)
CROSSREFS
Cf. A056730.
Sequence in context: A343714 A343715 A177678 * A059635 A003294 A096739
KEYWORD
nonn,base
AUTHOR
Robert G. Wilson v, Dec 18 2000
STATUS
approved