cp's OEIS Frontend

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.

A344341 Gray-code Niven numbers: numbers divisible by the number of 1's in their binary reflected Gray code (A005811).

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%I A344341 #8 May 16 2021 02:41:24
%S A344341 1,2,3,4,6,7,8,9,12,14,15,16,20,24,27,28,30,31,32,33,36,39,40,42,44,
%T A344341 45,48,51,52,56,57,60,62,63,64,68,72,75,76,80,84,88,90,92,96,99,100,
%U A344341 104,105,108,111,112,116,120,123,124,126,127,128,129,132,135,136
%N A344341 Gray-code Niven numbers: numbers divisible by the number of 1's in their binary reflected Gray code (A005811).
%H A344341 Amiram Eldar, <a href="/A344341/b344341.txt">Table of n, a(n) for n = 1..10000</a>
%H A344341 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/GrayCode.html">Gray Code</a>.
%H A344341 Wikipedia, <a href="https://en.wikipedia.org/wiki/Gray_code">Gray code</a>.
%e A344341 2 is a term since its Gray code is 11 and 1+1 = 2 is a divisor of 2.
%e A344341 6 is a term since its Gray code is 101 and 1+0+1 = 2 is a divisor of 6.
%t A344341 gcNivenQ[n_] := Divisible[n, DigitCount[BitXor[n, Floor[n/2]], 2, 1]]; Select[Range[150], gcNivenQ]
%Y A344341 Cf. A005811, A014550.
%Y A344341 Subsequences: A344342, A344343, A344344.
%Y A344341 Similar sequences: A005349 (decimal), A049445 (binary), A064150 (ternary), A064438 (quaternary), A064481 (base 5), A118363 (factorial), A328208 (Zeckendorf), A328212 (lazy Fibonacci), A331085 (negaFibonacci), A333426 (primorial), A334308 (base phi), A331728 (negabinary), A342426 (base 3/2), A342726 (base i-1).
%K A344341 nonn,base
%O A344341 1,2
%A A344341 _Amiram Eldar_, May 15 2021