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 A341596 #13 Nov 01 2024 05:14:55
%S A341596 0,1,1,1,1,2,1,2,1,2,1,3,1,2,2,2,1,3,1,2,2,2,1,3,1,2,2,2,1,4,1,2,2,2,
%T A341596 2,3,1,2,2,3,1,4,1,2,3,2,1,4,1,3,2,2,1,4,2,3,2,2,1,5,1,2,3,2,2,4,1,2,
%U A341596 2,4,1,4,1,2,3,2,2,4,1,3,2,2,1,5,2,2,2
%N A341596 Number of strictly inferior squarefree divisors of n.
%C A341596 We define a divisor d|n to be strictly inferior if d < n/d. Strictly inferior divisors are counted by A056924 and listed by A341674.
%H A341596 Amiram Eldar, <a href="/A341596/b341596.txt">Table of n, a(n) for n = 1..10000</a>
%e A341596 The strictly inferior squarefree divisors of selected n:
%e A341596 n = 1 2 6 12 30 60 120 210 240 420 630 1050 1260
%e A341596 --------------------------------------------------------
%e A341596 {} 1 1 1 1 1 1 1 1 1 1 1 1
%e A341596 2 2 2 2 2 2 2 2 2 2 2
%e A341596 3 3 3 3 3 3 3 3 3 3
%e A341596 5 5 5 5 5 5 5 5 5
%e A341596 6 6 6 6 6 6 6 6
%e A341596 10 7 10 7 7 7 7
%e A341596 10 15 10 10 10 10
%e A341596 14 14 14 14 14
%e A341596 15 15 15 15
%e A341596 21 21 21
%e A341596 30 30
%e A341596 35
%t A341596 Table[Length[Select[Divisors[n],SquareFreeQ[#]&&#<n/#&]],{n,100}]
%o A341596 (PARI) a(n) = sumdiv(n, d, d^2 < n && issquarefree(d)); \\ _Amiram Eldar_, Nov 01 2024
%Y A341596 Positions of ones are A000430.
%Y A341596 The weakly inferior version is A333749.
%Y A341596 The version counting odd instead of squarefree divisors is A333805.
%Y A341596 The version counting prime instead of squarefree divisors is A333806.
%Y A341596 The weakly superior version is A341592.
%Y A341596 The strictly superior version is A341595.
%Y A341596 The version counting prime-power instead of squarefree divisors is A341677.
%Y A341596 A001221 counts prime divisors, with sum A001414.
%Y A341596 A001222 counts prime power divisors.
%Y A341596 A005117 lists squarefree numbers.
%Y A341596 A033676 selects the greatest inferior divisor.
%Y A341596 A033677 selects the smallest superior divisor.
%Y A341596 A038548 counts superior (or inferior) divisors.
%Y A341596 A056924 counts strictly superior (or strictly inferior) divisors.
%Y A341596 A207375 lists central divisors.
%Y A341596 - Inferior: A063962, A066839, A069288, A161906, A217581, A333750.
%Y A341596 - Superior: A051283, A059172, A063538, A063539, A070038, A116882, A116883, A161908, A341591, A341593, A341675, A341676.
%Y A341596 - Strictly Inferior: A060775, A070039, A341674.
%Y A341596 - Strictly Superior: A048098, A064052, A140271, A238535, A341594, A341642, A341643, A341644, A341645, A341646, A341673.
%Y A341596 Cf. A000005, A000203, A001055, A001248, A050320.
%K A341596 nonn
%O A341596 1,6
%A A341596 _Gus Wiseman_, Feb 23 2021