

A085306


Prime numbers such that first reversing digits and after squaring equals the result of firstsquaring and afterreversing. Primes in A085305.


3



2, 3, 11, 13, 31, 101, 103, 113, 211, 311, 1013, 1021, 1031, 1103, 1201, 1301, 2011, 2111, 3001, 3011, 10103, 10111, 10211, 11003, 11113, 12011, 12101, 13001, 20011, 20021, 20101, 20201, 21001, 21011, 21101, 22111, 30011, 100003, 100103, 101021
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OFFSET

1,1


LINKS

Donovan Johnson, Table of n, a(n) for n = 1..1000


FORMULA

Prime number solutions to rev(x^2) = rev(x)^2.


EXAMPLE

n=13 is here because 31^2 = 961 = rev(169) = rev(13^2) = rev(rev(31)^2).
65 solutions below 1000000.


MATHEMATICA

rt[x_] := tn[Reverse[IntegerDigits[x]]] Do[s=rt[n^2]; s1=rt[n]^2; If[Equal[s, s1]&& !Equal[Mod[n, 10], 0]&&PrimeQ[n], Print[n]], {n, 1, 1000000}]


CROSSREFS

Cf. A085305.
Sequence in context: A157884 A234530 A235632 * A161322 A123239 A048891
Adjacent sequences: A085303 A085304 A085305 * A085307 A085308 A085309


KEYWORD

base,nonn


AUTHOR

Labos Elemer, Jun 27 2003


STATUS

approved



