OFFSET
1,1
LINKS
K. D. Bajpai, Table of n, a(n) for n = 1..4250
EXAMPLE
a(1)= 7, it is prime: prime(4)= 7: reversal(7^2)+7= reversal(49)+7= 94+7= 101 which is also prime.
a(2)= 151, it is prime: prime(36)= 151: reversal(151^2)+151= reversal(22801)+151=10822+151= 10973 which is also prime.
MAPLE
with(StringTools): KD:= proc() local a, p; p:=ithprime(n); a:= parse(Reverse(convert((p^2), string)))+p; if isprime(a) then RETURN (p): fi; end: seq(KD(), n=1..3000);
MATHEMATICA
Select[Prime[Range[3000]], PrimeQ[# + FromDigits[Reverse[IntegerDigits[#^2]]]] &]
CROSSREFS
KEYWORD
nonn
AUTHOR
K. D. Bajpai, Nov 24 2013
STATUS
approved