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%I #11 Aug 26 2020 02:56:10
%S 21,27,45,63,65,69,81,87,201,207,211,213,218,219,225,231,235,237,238,
%T 243,249,253,255,259,261,267,273,275,279,285,291,293,297,299,401,403,
%U 405,407,411,417,422,423,429,435,441,445,446,447,453,459,463,465,471
%N Deficient numbers whose reversal is an abundant number.
%H Amiram Eldar, <a href="/A098768/b098768.txt">Table of n, a(n) for n = 1..10000</a> (terms 1..1000 from Harvey P. Dale)
%e a(1) = 21 because 21 is a deficient number whose reversal, 12, is an abundant number.
%t dnanQ[n_]:=Module[{rev=FromDigits[Reverse[IntegerDigits[n]]]}, DivisorSigma[ 1,n]<2n&&DivisorSigma[1,rev]>2rev]; Select[Range[500],dnanQ] (* _Harvey P. Dale_, Apr 06 2013 *)
%Y Cf. A004086, A005100, A005101, A098770.
%K easy,nonn,base
%O 1,1
%A _Shyam Sunder Gupta_, Oct 02 2004