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 A331970 #8 Feb 04 2020 03:57:12 %S A331970 0,1,1,1,1,6,1,7,1,8,1,8,1,10,9,11,1,12,1,10,11,14,1,36,1,16,13,12,1, %T A331970 42,1,31,15,20,13,14,1,22,17,50,1,54,1,16,15,26,1,60,1,28,21,18,1,66, %U A331970 17,64,23,32,1,60,1,34,17,55,19,78,1,22,27,74,1,78,1 %N A331970 The sum of the proper bi-unitary divisors of n. %C A331970 First differs from A126168 at n = 16. %H A331970 Amiram Eldar, <a href="/A331970/b331970.txt">Table of n, a(n) for n = 1..10000</a> %F A331970 a(n) = A188999(n) - n. %e A331970 a(6) = 6 since A188999(6) - 6 = 12 - 6 = 6. %t A331970 fun[p_, e_] := If[OddQ[e], (p^(e+1)-1)/(p-1), (p^(e+1)-1)/(p-1)-p^(e/2)]; bsigma[1] = 1; bsigma[n_] := bsigma[n] = Times @@ (fun @@@ FactorInteger[n]); bs[n_] := bsigma[n] - n; Array[bs, 100] %Y A331970 Cf. A001065, A034460, A126164, A126168, A188999, A222266. %K A331970 nonn %O A331970 1,6 %A A331970 _Amiram Eldar_, Feb 03 2020