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 A071594 #18 Jan 11 2020 06:34:10 %S A071594 2,4,6,8,10,12,16,18,20,24,32,33,34,36,40,42,48,64,65,68,70,72,80,84, %T A071594 96,128,129,136,138,140,144,160,168,192,210,256,266,272,273,276,280, %U A071594 288,290,320,322,330,336,384,385,390,420,512,513,514,518,522,530,532 %N A071594 Numbers k such that the number of 1's in the binary representation of k equals omega(k), the number of distinct primes in the factorization of k. %H A071594 Amiram Eldar, <a href="/A071594/b071594.txt">Table of n, a(n) for n = 1..10000</a> (terms 1..2000 from Ivan Neretin) %e A071594 129 = 10000001 in base 2 and 129 = 3*43 hence 129 is in the sequence. %t A071594 Select[Range[2, 1000], Length[FactorInteger[#]] == DigitCount[#, 2, 1] &] (* _Ivan Neretin_, May 30 2015 *) %o A071594 (PARI) for(n=1,1000,if(sum(i=1,length(binary(n)), component(binary(n),i))==omega(n),print1(n,","))) %o A071594 (PARI) select(n->hammingweight(n)==omega(n), vector(1000, n, n)) \\ _Michel Marcus_, May 30 2015 %Y A071594 Cf. A071595, A071596, A071814. %K A071594 base,easy,nonn %O A071594 1,1 %A A071594 _Benoit Cloitre_, Jun 01 2002 %E A071594 Name edited by _Amiram Eldar_, Jan 11 2020