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 A161641 #8 Jan 01 2018 21:24:19 %S A161641 0,1,2,3,8,9,10,11,12,13,14,15,16,17,18,19,24,25,26,27,32,33,34,35,40, %T A161641 41,42,43,44,45,46,47,48,49,50,51,56,57,58,59,60,61,62,63,64,65,66,67, %U A161641 72,73,74,75,76,77,78,79,80,81,82,83,88,89,90,91,96,97,98,99,104,105,106,107,108 %N A161641 Positions n such that A010060(n) + A010060(n+4) = 1. %C A161641 Also union of all numbers of the form A131323(n)-k, k=0, 1, 2, or 3. %H A161641 G. C. Greubel, <a href="/A161641/b161641.txt">Table of n, a(n) for n = 1..10000</a> %F A161641 A001477 \ A161627. %t A161641 tm[0] = 0; tm[n_?EvenQ] := tm[n] = tm[n/2]; tm[n_] := tm[n] = 1 - tm[(n - 1)/2]; Reap[For[n = 0, n <= 16000, n++, If[tm[n] + tm[n + 4] == 1, Sow[n]]]][[2, 1]] (* _G. C. Greubel_, Jan 01 2018 *) %o A161641 (PARI) is(n)=hammingweight(n)%2!=hammingweight(n+4)%2 \\ _Charles R Greathouse IV_, Aug 20 2013 %Y A161641 Cf. A161639, A161627, A161579, A161580, A079523, A131323, A036554, A010060, A121539, A079523, A081706. %K A161641 nonn %O A161641 1,3 %A A161641 _Vladimir Shevelev_, Jun 15 2009 %E A161641 More terms from _R. J. Mathar_, Aug 17 2009