A343714 Palindromic primes of the form p//q//reverse(p), where p is a prime (not necessarily palindromic) and q, of course, is a palindromic prime.

353, 373, 727, 757, 11311, 13331, 19391, 31013, 31513, 33533, 37273, 37573, 39293, 71317, 71917, 73237, 77977, 79397, 97379, 97579, 1035301, 1092901, 1093901, 1175711, 1178711, 1273721, 1317131, 1335331, 1338331, 1513151, 1572751, 1633361, 1737371, 1793971

Offset: 1

Author

Jon E. Schoenfield, May 08 2021

Keywords

• nonn
• base

Comments

Note that reverse(p) need not be a prime; e.g., a(7)=19391 is the concatenation of 19, 3, and 91=7*13. If a requirement were added that reverse(p) also be a prime, the result would be sequence A343715.

Examples

			353 is a term because it is a palindromic prime (A002385) and is the concatenation of 3 (a prime), 5 (a palindromic prime), and 3 (the reverse of 3).
31513 is a term in two ways: as the concatenation 3//151//3 and as the concatenation 31//5//13.
7392937 is a term in three ways: 7//39293//7, 73//929//37, and 739//2//937.
		

Crossrefs

Cf. A002385, A045336, A177678, A343715.