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%I #15 May 27 2018 13:36:27
%S 4,9,94,46,121,961,982,4,526,9,169,6511,5221,9481,1042,6313,4633,1843,
%T 1273,94,1405,9235,46,9886,6937,4069,10201,61801,94411,18811,121,
%U 44521,96721,52231,65431,42931,67351,52651,92161,48361,961,16171,98671,65971,96781
%N Sp = reversal of some square s where s = x^2 for x = 1,2,.. (ignoring leading zeros). Sp is in the sequence if it is semiprime.
%C All the terms in sequence are semiprimes (product of two primes) which are reversal of some square, ignoring leading zeros.
%H K. D. Bajpai, <a href="/A242097/b242097.txt">Table of n, a(n) for n = 1..360</a>
%e a(3) = 94 = 2 * 47 which is semiprime. Reversing the digits gives 49 = 7^2.
%e a(4) = 46 = 2 * 23 which is semiprime. Reversing the digits gives 64 = 8^2.
%p with(StringTools): with(numtheory): A242097:= proc() local r; r:= parse(Reverse(convert(x^2,string))); if bigomega(r)=2 then RETURN (r); fi; end: seq(A242097 (), x=1..500);
%t Select[IntegerReverse[Range[200]^2],PrimeOmega[#]==2&] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, May 27 2018 *)
%Y Cf. A001358, A115710, A115711.
%K nonn,base,less
%O 1,1
%A _K. D. Bajpai_, May 04 2014