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 A331728 #15 Jan 28 2020 03:57:16 %S A331728 1,2,3,4,6,8,9,12,14,15,16,18,20,21,24,28,30,32,33,35,36,40,42,48,50, %T A331728 52,54,56,57,60,62,63,64,66,68,69,72,76,78,80,81,84,88,90,91,95,96, %U A331728 100,102,108,110,112,114,120,124,125,126,128,129,132,136,138,140 %N A331728 Negabinary-Niven numbers: numbers divisible by the sum of digits in their negabinary representation (A027615). %H A331728 Amiram Eldar, <a href="/A331728/b331728.txt">Table of n, a(n) for n = 1..10000</a> %e A331728 6 is a term since A039724(6) = 11010 and 1 + 1 + 0 + 1 + 0 = 3 is a divisor of 6. %t A331728 negaBinWt[n_] := negaBinWt[n] = If[n==0, 0, negaBinWt[Quotient[n-1, -2]] + Mod[n, 2]]; negaBinNivenQ[n_] := Divisible[n, negaBinWt[n]]; Select[Range[100], negaBinNivenQ] %Y A331728 Cf. A027615, A039724, A005349, A049445, A328208, A328212, A331085, A331088. %K A331728 nonn,base %O A331728 1,2 %A A331728 _Amiram Eldar_, Jan 27 2020