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 A294890 #13 Mar 14 2024 03:48:12
%S A294890 0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,1,0,1,0,0,0,1,0,0,0,0,0,1,0,0,0,0,
%T A294890 0,2,0,0,0,1,0,1,0,0,0,0,0,1,0,0,0,0,0,1,0,1,0,0,0,3,0,0,0,0,0,1,0,0,
%U A294890 0,1,0,2,0,0,0,0,0,1,0,1,0,0,0,2,0,0,0,1,0,2,0,0,0,0,0,1,0,0,0,1,0,1,0,1,0,0,0,2,0,0,0,1,0,1,0,0,0,0,0,3
%N A294890 Number of divisors of n that are primitively abundant (A091191).
%C A294890 Records occur at 1, 12, 36, 60, 180, 420, 840, 2520, 7560, 9240, 24024, 60060, ... and they are 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 13, ... Ten occurs for the first time as a(40040) = 10.
%H A294890 Antti Karttunen, <a href="/A294890/b294890.txt">Table of n, a(n) for n = 1..70560</a>
%F A294890 a(n) = Sum_{d|n} A294930(d).
%e A294890 Divisors of 24 are 1, 2, 3, 4, 6, 8, 12, 24. Only 12 is in A091191, thus a(24) = 1.
%e A294890 Divisors of 36 are 1, 2, 3, 4, 6, 9, 12, 18, 36. Of these 12 and 18 are found in A091191, thus a(36) = 2.
%t A294890 q[n_] := Count[Divisors[n], _?(DivisorSigma[1, #] > 2*# &)] == 1; a[n_] := DivisorSum[n, 1 &, q[#] &]; Array[a, 100] (* _Amiram Eldar_, Mar 14 2024 *)
%o A294890 (PARI)
%o A294890 A294937(n) = (sigma(n)>(2*n));
%o A294890 A294929(n) = sumdiv(n, d, (d<n)*A294937(d));
%o A294890 A294930(n) = (A294937(n)*(0==A294929(n)));
%o A294890 A294890(n) = sumdiv(n, d, A294930(d));
%Y A294890 Cf. A080224, A091191, A294930.
%K A294890 nonn
%O A294890 1,36
%A A294890 _Antti Karttunen_, Nov 14 2017