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%I #11 May 07 2023 12:54:02
%S 1,2,3,5,6,7,12,17,18,19,21,22,23,25,26,27,29,30,31,32,33,34,35,36,37,
%T 38,39,40,48,65,66,67,69,70,71,76,84,88,92,97,98,99,101,102,103,108,
%U 113,114,115,117,118,119,124,128,129,130,131,133,134,135,140,144,145,146,147,149,150,151,153,154,155,157,158
%N Indices of 1's in A361897.
%H Paolo Xausa, <a href="/A362454/b362454.txt">Table of n, a(n) for n = 1..20000</a> (terms 1..4750 from N. J. A. Sloane)
%t A362454[upto_]:=Module[{d=DivisorSigma[0,Range[upto]]},Join[{1},Table[If[First[d=Abs[Differences[d]]]==1,n,Nothing],{n,2,upto}]]];A362454[200] (* _Paolo Xausa_, May 07 2023 *)
%Y Cf. A361897, A362450, A362453.
%K nonn
%O 1,2
%A _N. J. A. Sloane_, May 05 2023