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 A331819 #8 Jan 28 2020 03:57:21 %S A331819 2,3,4,6,8,9,10,12,15,16,18,20,24,25,27,28,30,32,33,34,36,39,40,42,44, %T A331819 48,54,55,56,60,63,64,66,68,70,72,77,78,80,84,90,92,96,100,102,104, %U A331819 108,111,112,114,115,116,120,123,124,126,128,129,130,132,135,136,138,140 %N A331819 Positive numbers k such that -k is a negative negabinary-Niven number, i.e., divisible by the sum of digits of its negabinary representation (A027615). %H A331819 Amiram Eldar, <a href="/A331819/b331819.txt">Table of n, a(n) for n = 1..10000</a> %e A331819 6 is a term since A039724(-6) = 1110 and 1 + 1 + 1 + 0 = 3 is a divisor of 6. %t A331819 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 A331819 Cf. A005352, A027615, A039724, A005349, A049445, A328208, A328212, A331085, A331088, A331728. %K A331819 nonn,base %O A331819 1,1 %A A331819 _Amiram Eldar_, Jan 27 2020