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 A331825 #8 Jan 28 2020 03:56:54
%S A331825 413,2093,3773,4613,7133,7973,8813,10493,11869,15829,16373,23749,
%T A331825 30653,31493,34853,35629,37373,39589,40733,49133,51469,54585,55429,
%U A331825 63349,64253,65513,67613,70965,75229,91069,98989,102949,103725,106909,110869,114653,129773,131033
%N A331825 Positive numbers k such that -k, -(k + 1), -(k + 2), and -(k + 3) are 4 consecutive negative negabinary-Niven numbers (A331728).
%H A331825 Amiram Eldar, <a href="/A331825/b331825.txt">Table of n, a(n) for n = 1..10000</a>
%t A331825 negaBinWt[n_] := negaBinWt[n] = If[n == 0, 0, negaBinWt[Quotient[n - 1, -2]] + Mod[n, 2]]; negaBinNivenQ[n_] := Divisible[n, negaBinWt[-n]]; nConsec = 4; neg = negaBinNivenQ /@ Range[nConsec]; seq = {}; c = 0; k = nConsec+1; While[c < 45, If[And @@ neg, c++; AppendTo[seq, k - nConsec]]; neg = Join[Rest[neg], {negaBinNivenQ[k]}]; k++]; seq
%Y A331825 Cf. A027615, A039724, A141769, A328211, A328215, A330933, A331728, A331824.
%K A331825 nonn,base
%O A331825 1,1
%A A331825 _Amiram Eldar_, Jan 27 2020