A227780 Emirps p such that p plus its decimal reversal is a perfect square.

303593, 333563, 336263, 342653, 344453, 348053, 350843, 354443, 356243, 362633, 365333, 395303, 744377, 754367, 755267, 762557, 763457, 773447, 3014393, 3204473, 3214373, 3444053, 3504443, 3734123, 3744023, 3934103, 79099019, 91099097, 100771943, 101078843

Offset

1,1

Comments

303593 is the smallest emirp to satisfy the requirement.

Links

Shyam Sunder Gupta, Table of n, a(n) for n = 1..310

Chris K. Caldwell and G. L. Honaker, Jr., Prime Curios! 303593

Example

a(1) = 303593: Reversing the digits gives 395303 and 303593 + 395303 = 698896 = 836^2.

Mathematica

t = {}; Do[n = Prime[x]; m = FromDigits[Reverse[IntegerDigits[Prime[x]]]]; If[IntegerQ[(n + m)^(1/2)] && PrimeQ[m] && m!=n, AppendTo[t, n]], {x, 1, 7000000}]; t

Crossrefs

Cf. A006567, A059799.

Sequence in context: A212230 A185852 A053849 * A237950 A116888 A270764

Adjacent sequences: A227777 A227778 A227779 * A227781 A227782 A227783

Keyword

nonn,base

Author

Shyam Sunder Gupta, Aug 17 2013

Status

approved