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%I #14 Aug 26 2020 02:55:54
%S 12,18,20,30,36,40,54,56,70,72,78,80,90,96,100,102,104,108,112,114,
%T 120,126,132,138,140,144,150,156,160,162,168,174,176,180,186,192,196,
%U 198,200,208,220,224,260,280,300,304,306,308,312,318,320,324,330,336,340
%N Abundant numbers whose reversal is a deficient number.
%H Amiram Eldar, <a href="/A098770/b098770.txt">Table of n, a(n) for n = 1..10000</a>
%e a(2) = 18 because 18 is the second abundant number which on reversing its digits gives a deficient number, namely 81.
%t rev[n_] := FromDigits @ Reverse @ IntegerDigits[n]; Select[Range[340], DivisorSigma[1, #] > 2*# && DivisorSigma[1, (r = rev[#])] < 2*r &] (* _Amiram Eldar_, Aug 26 2020 *)
%Y Cf. A004086, A005100, A005101, A098768.
%K easy,nonn,base
%O 1,1
%A _Shyam Sunder Gupta_, Oct 02 2004
%E Edited by _N. J. A. Sloane_ at the suggestion of _Andrew S. Plewe_, May 21 2007
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