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%I #14 Aug 08 2019 07:42:19
%S 1,64,524,534,58725,907538,6264385,9438088,9596598,27895162,422984004,
%T 548911025,8804661048,49640253574,63899981216,95138721219,97895906839,
%U 469449672154
%N Numbers n such that n is R(n)-th nonprime number, where R(n) is the digit reversal of n (A018252(A004086(n))=n).
%C n is in the sequence iff n is not prime and R(n)=n-pi(n). There is no further term up to 3670000000.
%C a(19) > 10^13. Up to that limit, this sequence contains all the numbers k such that R(k) = k - pi(k). - _Giovanni Resta_, Aug 08 2019
%e 548911025 is in the sequence because 548911025 is the 520118945th nonprime natural number.
%t Do[s = FromDigits[Reverse[IntegerDigits[n]]]; If[ ! PrimeQ[n] && s == n - PrimePi[n], Print[n]], {n, 548911025}]
%Y Cf. A018252, A004086, A100413, A100414, A114926.
%K nonn,base,more
%O 1,2
%A _Farideh Firoozbakht_, Dec 12 2004
%E a(13)-a(18) from _Giovanni Resta_, Aug 08 2019
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