A177678 Palindromic primes p = q//r//q such that q and r are also palindromic primes.

353, 373, 727, 757, 11311, 31013, 31513, 33533, 37273, 37573, 39293, 71317, 71917, 77977, 1175711, 1178711, 1317131, 1513151, 1917191, 3103013, 3106013, 3127213, 3135313, 3155513, 3160613, 3166613, 3181813, 3193913, 3198913, 3304033

Offset: 1

Author

Eva-Maria Zschorn (e-m.zschorn(AT)zaschendorf.km3.de), May 10 2010

Keywords

• nonn
• base

Comments

p = palprime(i), q = palprime(j), r = palprime(k) (see A002385).

Indices (i,j,k): (12,2,3), (13,2,4), (15,4,1), (16,4,3), (24,5,2), (52,2,6), (53,2,8), (56,2,12), (65,2,15), (66,2,16), (70,2,20), (74,4,7), (75,4,10), (88,4,18), (140,11,16), (142,11,17), (174,7,4), (206,8,2), (282,10,4), (318,2,21), (319,2,23), (320,2,27), (321,11,3), (323,2,35), (325,2,36), (326,2,39), (327,2,42), (329,2,44), (331,2,45), (354,2,49), (356,2,50), (357,2,52), (358,2,53), (365,2,61), (366,2,63), (368,2,64), (370,2,67), (372,2,70), (424,2,76), (426,2,79), (430,2,84), (434,2,86), (435,2,87), (437,2,89), (439,2,92), (440,2,94), (464,2,97), (467,2,102), (468,2,103), (469,2,107).

Note an example that the description with q and r is not (necessarily) unique: (2388,2,179) or (2388,11,14) for 313383313 = 3//1338331//3 = 313//383//313.

Examples

			3 = palprime(2), 5 = palprime(3), 3//5//3 = 353 = palprime(12) is first term.
3 = palprime(2), 7 = palprime(4), 3//7//3 = 373 = palprime(13) is 2nd term.
		

References

• M. Gardner: Mathematischer Zirkus, Ullstein Berlin-Frankfurt/Main-Wien, 1988
• K. G. Kroeber: Ein Esel lese nie. Mathematik der Palindrome, Rowohlt Tb., Hamburg, 2003

Crossrefs

Cf. A002385, A176465.