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.

A320008 a(0) = 1; for n > 0, a(n) = A000120(n) * a(n-A000120(n)), where A000120(n) is the binary weight of n.

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%I A320008 #10 Dec 20 2018 23:17:29
%S A320008 1,1,1,2,2,4,4,6,6,12,12,18,24,36,54,72,72,144,144,216,288,432,648,
%T A320008 864,1296,1944,2592,3456,5832,7776,10368,12960,12960,25920,25920,
%U A320008 38880,51840,77760,116640,155520,233280,349920,466560,622080,1049760,1399680,1866240,2332800,3732480,5598720,6998400,9331200,16796160,22394880,27993600,34992000
%N A320008 a(0) = 1; for n > 0, a(n) = A000120(n) * a(n-A000120(n)), where A000120(n) is the binary weight of n.
%C A320008 Sequence is monotonic because A011371 is.
%H A320008 Antti Karttunen, <a href="/A320008/b320008.txt">Table of n, a(n) for n = 0..133</a>
%H A320008 <a href="/index/Bi#binary">Index entries for sequences related to binary expansion of n</a>
%F A320008 a(0) = 1; for n > 0, a(n) = A000120(n) * a(n-A000120(n)).
%t A320008 Nest[Append[#1, #2 #1[[-#2]] ] & @@ {#, Total@ IntegerDigits[Length@ #, 2]} &, {1}, 55] (* _Michael De Vlieger_, Nov 25 2018 *)
%o A320008 (PARI) A320008(n) = if(0==n,1,hammingweight(n)*A320008(n-hammingweight(n)));
%Y A320008 Cf. A000120, A011371, A179016.
%Y A320008 Cf. also A320002, A320009.
%K A320008 nonn
%O A320008 0,4
%A A320008 _Antti Karttunen_, Nov 24 2018