A075807 Numbers n such that n-th prime is palindromic.

1, 2, 3, 4, 5, 26, 32, 36, 42, 43, 65, 71, 74, 76, 129, 134, 138, 139, 157, 158, 1263, 1285, 1293, 1367, 1377, 1483, 1519, 1528, 1583, 1635, 1647, 1682, 1726, 1805, 1814, 1867, 1897, 1917, 1928, 2009, 2060, 2083, 2117, 2196, 2250, 2260, 3255, 3267, 3285

Offset: 1

Author

Jani Melik, Oct 13 2002

Keywords

• nonn
• base

Examples

			26th prime is 101, which is palindromic.
		

Links

• Chai Wah Wu, Table of n, a(n) for n = 1..10000 (n = 1..781 from Vincenzo Librandi, n = 782..5373 from David A. Corneth)

Crossrefs

Cf. A000720, A002385, A069217.

Programs

Magma

[n: n in [1..3500] | Intseq(NthPrime(n), 10) eq Reverse(Intseq(NthPrime(n), 10))]; // Vincenzo Librandi, Mar 24 2019

Maple

test := proc(n) local d; d := convert(ithprime(n),base,10); return ListTools[Reverse](d)=d; end; a := []; for n from 1 to 4000 do if test(n) then a := [op(a),n]; end; od; a;

Mathematica

Rest[Flatten[Position[Prime[Range[4000]],?(IntegerDigits[#] == Reverse[ IntegerDigits[#]]&)]]] (* _Harvey P. Dale, Jan 26 2014 *)

PARI

isok(n) = my(d=digits(prime(n))); Vecrev(d) == d; \\ Michel Marcus, Mar 24 2019

Formula

a(n) = A000720(A002385(n)). - David A. Corneth, Mar 24 2019

Extensions

Edited by Dean Hickerson, Oct 21 2002