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 A161449 #4 Jan 25 2018 10:04:02 %S A161449 9,24,43,58,77,92,111,126,129,144,163,178,197,212,231,246,264,281,298, %T A161449 315,332,349,366,383,384,401,418,435,452,469,486,503,523,538,553,568, %U A161449 591,606,621,636,643,658,673,688,711,726,741,756,778,795,808,825,846 %N A161449 Numbers n such that A160700(n) = 9. %H A161449 Charles R Greathouse IV, <a href="/A161449/b161449.txt">Table of n, a(n) for n = 1..10000</a> %F A161449 16n - 16 <= a(n) <= 16n - 1. - _Charles R Greathouse IV_, Jan 25 2018 %o A161449 (PARI) A160700(n)=my(t=n%16); while(n>15, n>>=4; t=bitxor(t, n%16)); t %o A161449 a(n)=for(k=16*n-16, 16*n-1, if(a(k)==9, return(k))) \\ _Charles R Greathouse IV_, Jan 25 2018 %Y A161449 Cf. A161440, A161441, A161442, A161443, A161444, A161445, A161446, A161447, A161448, A161450, A161451, A161452, A161453, A161454, A161455. %K A161449 nonn,easy %O A161449 1,1 %A A161449 _Reinhard Zumkeller_, Jun 10 2009