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Search: id:A063964
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%I A063964
%S A063964 11,14,224,957,1334,1634,2685,9347,13915,16260,20145,20335,33998,37236,
%T A063964 42251,42818,51624,55308,56419,56975,71874,74918,77748,79824,79826,
%U A063964 79833,84134,93632,106600,111506,120680,122073,138237,142116,147454
%N A063964 Numbers n such that n and n+1 have the same sum of square-free divisors, 
               or sqf(n)=sqf(n+1), where sqf(n) = A048250(n).
%H A063964 Harry J. Smith, <a href="b063964.txt">Table of n, a(n) for n=1,...,170</
               a>
%o A063964 (PARI) sqf(n) = sumdiv(n,d, if(issquarefree(d),d,0)); for(n=1,10^7, if(sqf(n)==sqf(n+1),
               print(n)))
%o A063964 (PARI) { n=0; s=0; for (m=1, 10^9, t=sumdiv(m + 1, d, if(issquarefree(d), 
               d, 0)); if(s==t, write("b063964.txt", n++, " ", m); if (n==170, break)); 
               s=t ) } [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), Sep 04 
               2009]
%Y A063964 Cf. A048250.
%Y A063964 Sequence in context: A043885 A101840 A061087 this_sequence A139065 A111322 
               A069822
%Y A063964 Adjacent sequences: A063961 A063962 A063963 this_sequence A063965 A063966 
               A063967
%K A063964 easy,nonn
%O A063964 1,1
%A A063964 Jason Earls (zevi_35711(AT)yahoo.com), Sep 04 2001

    
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Last modified November 30 13:13 EST 2009. Contains 167758 sequences.


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