A059799 Primes which when added to their reversals are squares.

2, 29, 47, 83, 263, 461, 20147, 23117, 24107, 63113, 80141, 81131, 300893, 301793, 303593, 308093, 310883, 313583, 324473, 333563, 336263, 342653, 344453, 348053, 350843, 354443, 355343, 356243, 362633, 363533, 364433, 365333, 377123, 378023

Offset: 1

Author

Enoch Haga, Feb 23 2001

Keywords

• easy
• nonn
• base

Comments

Idea from Carlos Rivera's The Prime Puzzles and Problems Connection, Conjecture 23.

Examples

			a(4)=263 because 263+362=625 and 625 is a square whose root is 25.
		

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..683 (all such primes up to the 20 millionth prime)

Crossrefs

Cf. A035519, A059798.

Cf. A227371 (indices of these primes).

Programs

Mathematica

Select[Prime[Range[33000]],IntegerQ[Sqrt[FromDigits[Reverse[ IntegerDigits[#]]]+ #]]&] (* Harvey P. Dale, Aug 18 2012 *)

Formula

Add prime to its reverse. If a square, add to sequence.