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%I #16 May 14 2022 11:59:44
%S 1,2,3,4,5,6,8,9,10,12,14,15,16,18,20,22,24,28,30,32,34,36,40,42,44,
%T 46,48,52,54,56,60,64,66,70,72,78,80,84,90,96,100,102,108,114,120,126,
%U 132,138,140,144,150,156,162,168,180,192,198,204,210,216,228
%N Numbers n such that sigma_2(n) > sigma_2(k) for all k < n.
%C Where record values of sigma_2(n) occur. Records transform of A001157.
%H Amiram Eldar, <a href="/A193988/b193988.txt">Table of n, a(n) for n = 1..10000</a> (terms 1..1000 from T. D. Noe)
%t mx = 0; t = {}; Do[u = DivisorSigma[2, n]; If[u > mx, mx = u; AppendTo[t, n]], {n, 1000}]; t
%t DeleteDuplicates[Table[{n,DivisorSigma[2,n]},{n,1000}],GreaterEqual[#1[[2]],#2[[2]]]&][[All,1]] (* _Harvey P. Dale_, May 14 2022 *)
%Y Cf. A001157, A002093 (highly abundant numbers), A193989.
%K nonn
%O 1,2
%A _T. D. Noe_, Aug 17 2011