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.

A322825 A variant of A322827.

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%I A322825 #11 Jan 17 2019 17:19:18
%S A322825 1,2,6,4,36,30,18,8,216,450,210,900,108,150,54,16,1296,6750,7350,
%T A322825 13500,44100,2310,22050,27000,648,2250,1470,4500,324,750,162,32,7776,
%U A322825 101250,257250,202500,1543500,177870,771750,405000,9261000,2668050,30030,5336100,4630500,889350,2315250,810000,3888,33750,51450,67500
%N A322825 A variant of A322827.
%H A322825 Antti Karttunen, <a href="/A322825/b322825.txt">Table of n, a(n) for n = 0..16383</a>
%H A322825 <a href="/index/Bi#binary">Index entries for sequences related to binary expansion of n</a>
%F A322825 A001221(a(n)) = A005811(n).
%F A322825 A001222(a(n)) = A227183(n).
%F A322825 A046523(a(n)) = A322827(n).
%o A322825 (PARI) A322825(n) = if(!n,1, my(rl=1, m=1, p=2, eb = (n%2)); n>>=1; while(n,if((n%2)==eb, rl++, eb = 1-eb; m *= p^rl; p = nextprime(1+p)); n >>= 1); m *= p^rl; (m));
%o A322825 (PARI) A322825(n) = if(!n,1,my(bits = Vecrev(binary(n)), rl=1, o = List([])); for(i=2,#bits,if(bits[i]==bits[i-1], rl++, listput(o,rl))); listput(o,rl); my(es=Vec(o), m=1); for(i=1,#es,m *= prime(i)^es[i]); (m));
%Y A322825 Cf. A005811, A227183, A322827 (the main entry).
%K A322825 nonn
%O A322825 0,2
%A A322825 _Antti Karttunen_, Jan 16 2019