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Numbers k such that k + (largest digit of k)! is a palindromic prime.
1

%I #9 Apr 14 2024 23:24:59

%S 1,10,100,253,6271,6371,12611,13621,15331,15431,15641,25763,26473,

%T 30187,30287,30713,31603,33743,34633,35033,35233,36553,38167,38467,

%U 38567,65167,65467,65567,66277,70517,71327,71627,72337,72437,73447,73747

%N Numbers k such that k + (largest digit of k)! is a palindromic prime.

%H Harvey P. Dale, <a href="/A095920/b095920.txt">Table of n, a(n) for n = 1..500</a>

%e 6271 is a term because 6271 + 7! = 11311.

%t ppQ[n_]:=Module[{c=n+Max[IntegerDigits[n]]!},PrimeQ[c]&&PalindromeQ[c]]; Select[Range[75000],ppQ] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Sep 30 2017 *)

%Y Cf. A054055, A002385.

%K base,nonn

%O 1,2

%A _Jason Earls_, Jul 11 2004