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%I #4 Jul 13 2014 17:08:06
%S 1001320,1001720,1002220,1004420,1005520,1005710,1005910,1006120,
%T 1007420,1008710,1009220,1009510,1009610,1011220,1011620,1012120,
%U 1014320,1015420,1015610,1015810,1016020,1017320,1018610,1019120,1019410,1019510,1021120,1021520
%N Nonprimes such that it takes exactly 5 iterations of reverse-and-add digits to generate a prime.
%e Reversing and adding starting with 1005710 -> 1180711 -> 2351522 -> 4603054 -> 9106118 -> 17222137 and 17222137 is prime while the prior numbers are not primes.
%t p5Q[n_]:=Module[{lst=NestList[#+FromDigits[Reverse[ IntegerDigits[#]]]&, n,5]},NoneTrue[Most[lst],PrimeQ]&&PrimeQ[Last[lst]]]; Select[ Range[ 3000000],p5Q] (* using NoneTrue function from Mathematica version 10 *)
%Y Cf. A245208, A245209
%K nonn,base
%O 0,1
%A _Harvey P. Dale_, Jul 13 2014
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