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.

A190468 Numbers with prime factorization pq^4r^5.

This page as a plain text file.
%I A190468 #10 May 13 2013 01:49:35
%S A190468 12960,18144,19440,27216,28512,33696,42768,44064,49248,50544,59616,
%T A190468 60000,66096,73872,75168,80352,89424,95904,106272,111456,112752,
%U A190468 120528,121824,137376,140000,143856,150000,152928,158112,159408,167184,173664
%N A190468 Numbers with prime factorization pq^4r^5.
%H A190468 T. D. Noe, <a href="/A190468/b190468.txt">Table of n, a(n) for n = 1..1000</a>
%H A190468 Will Nicholes, <a href="http://willnicholes.com/math/primesiglist.htm">Prime Signatures</a>
%t A190468 f[n_]:=Sort[Last/@FactorInteger[n]]=={1,4,5}; Select[Range[300000],f]
%o A190468 (PARI) list(lim)=my(v=List(),t1,t2);forprime(p=2, (lim\48)^(1/5), t1=p^5;forprime(q=2, (lim\t1)^(1/4), if(p==q, next);t2=t1*q^4;forprime(r=2, lim\t2, if(p==r||q==r, next);listput(v,t2*r)))); vecsort(Vec(v)) \\ _Charles R Greathouse IV_, Jul 20 2011
%Y A190468 Cf. A190466, A190467.
%K A190468 nonn
%O A190468 1,1
%A A190468 _Vladimir Joseph Stephan Orlovsky_, May 10 2011