This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A384232 #20 May 29 2025 00:13:52
%S A384232 1,3,6,20,42,84,156,312,684,1020,1380,1860,3480,3720,4920,7320,10980,
%T A384232 14640,16920,21960,26280,34920,45720,59640,69840,89880,106680,125160,
%U A384232 145320,177240,213360,244440,269640,354480,320040,375480,435960,456120,531720,647640,708120
%N A384232 Smallest number whose largest odd noncomposite divisor is its n-th divisor.
%C A384232 This coincide with A087134 except for the second term because here a(2) = 3 and there A087134(2) = 2.
%e A384232 The divisors of 42 are [1, 2, 3, 6, 7, 14, 21, 42] and the largest odd noncomposite divisor is 7 and 7 is its 5th divisor, so a(5) = 42 because 42 the smallest number having that property.
%t A384232 With[{t = Table[FirstPosition[Divisors[n], FactorInteger[n/2^IntegerExponent[n, 2]][[-1, 1]]][[1]], {n, 1, 10^6}]}, TakeWhile[FirstPosition[t, #] & /@ Range[Max[t]] // Flatten, ! MissingQ[#] &]] (* _Amiram Eldar_, May 23 2025 *)
%Y A384232 Row 1 of A384233.
%Y A384232 Companion of A383402.
%Y A384232 Cf. A006005, A027750, A087134.
%K A384232 nonn
%O A384232 1,2
%A A384232 _Omar E. Pol_, May 23 2025