A192140 Palindromic numbers m such that their concatenation of prime divisors are also palindromic numbers.

2, 3, 4, 5, 7, 8, 9, 11, 101, 121, 131, 151, 181, 191, 313, 343, 353, 373, 383, 727, 747, 757, 787, 797, 919, 929, 1331, 10001, 10201, 10301, 10501, 10601, 11311, 11411, 12421, 12721, 12821, 13331, 13831, 13931, 14341, 14641, 14741, 15451, 15551, 16061, 16361

Offset: 1

Author

Jaroslav Krizek, Jun 24 2011

Keywords

• nonn
• base

Comments

The corresponding values of palindromic concatenation in A192141.

Superset of A002385 (palindromic primes) and A084092 (prime power decimal palindromes).

Subset of A002113 (palindromic numbers) and A192137.

Examples

			Concatenation of prime divisors of number 747 = 3^2 * 83 is 383 (palindromic number).
		

Crossrefs

Cf. A002113, A002385, A084317, A084092, A192137, A192138, A192139, A192141.

Programs

Mathematica

f[n_] := FromDigits[Flatten[IntegerDigits /@ FactorInteger[n][[;; , 1]]]]; Select[Range[2, 20000], And @@ (PalindromeQ /@ {#, f[#]}) &] (* Amiram Eldar, Aug 06 2024 *)

Extensions

More terms from Amiram Eldar, Aug 06 2024