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 A331206 #8 Jan 16 2020 13:21:40 %S A331206 1,2,3,4,5,6,8,10,12,15,16,17,20,21,24,30,32,34,40,42,48,51,60,63,64, %T A331206 65,68,69,80,81,84,85,96,102,120,126,128,130,136,138,160,162,168,170, %U A331206 192,195,204,207,240,243,252,255,256,257,260,261,272,273,276,277 %N A331206 Numbers k such that A053985(k) divides k. %C A331206 It appears that A053985(a(n)) / a(n) is always either 1, -1, 3 or -3. %C A331206 This sequence seems to contain A329000. %e A331206 15 is written 1111 base 2 and (-2)^3 + (-2)^2 + (-2)^1 +(-2)^0 = -8 + 4 - 2 + 1 = -5, 15 is divisible by -5. %o A331206 (PARI) is(k) = k%fromdigits(binary(k), -2) == 0; \\ _Jinyuan Wang_, Jan 15 2020 %K A331206 nonn,base %O A331206 1,2 %A A331206 _Alon Ran_, Jan 12 2020