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Search: id:A126098
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%I A126098
%S A126098 1,2,4,6,12,24,30,60,120,180,210,360,420,840,1260,1680,2520,4620,7560,
%T A126098 9240,13860,18480,27720,55440,83160,110880,120120,180180,240240,360360,
%U A126098 720720,1081080,1441440,1801800,2042040,2882880,3063060,4084080,5405400,
               6126120,12252240,18378360,24504480
%N A126098 Where records occur in A018892.
%C A126098 Remarkably similar to but ultimately different from A018894. - Jorg Brown 
               and N. J. A. Sloane (njas(AT)research.att.com), Mar 06 2007
%C A126098 Comment from Ray Chandler (rayjchandler(AT)sbcglobal.net), Dec 04 2008: 
               This sequence represents "where records occur" for a number of sequences 
               in addition to A018892 including the following: A015995, A015999, 
               A016001, A016002, A016003, A016005, A016006, A016007, A016008, A016009, 
               A048691, A048785, A063647, A117677, A144943.
%C A126098 Subsequence of A025487. [From Ray Chandler (rayjchandler(AT)sbcglobal.net), 
               Sep 05 2008]
%C A126098 Also record-setting elements of tau(n^2) (just as A002182 gives the record-setting 
               elements of tau(n)). The point is that A018892 is (tau(n^2) + 1)/
               2. As tau(n^2) is odd, the record-setting elements of A018892 are 
               also the record setting elements of tau(n^2). - Allen Tracht, Jan 
               20 2009
%H A126098 Ray Chandler, <a href="b126098.txt">Table of n, a(n) for n=1..103</a>
%H A126098 Jorg Brown, <a href="a018894.txt">Comparison of records in sigma(n)/phi(n) 
               and A018892</a>
%o A126098 // This C++ program generates the sequence of n for which A018892 sets 
               a new record. It takes one argument, defaulting to 300, which is 
               the maximum record that it's looking for. int main(int argc, char 
               *argv[]) { int limit = (argc != 2) ? 300 : atoi(argv[1]); int maxsol 
               = 0; for (unsigned int n = 2*3*5;; n += 2*3*5) { int numsol = 0; 
               for (uint64_t x = n + 1; x <= n + n; ++x) { uint64_t y = x * n / 
               (x - n); if (y * (x - n) == x * n) { numsol++; } } if (numsol > maxsol) 
               { printf("New max n=%d sols=%d ", n, numsol); maxsol = numsol; } 
               if (numsol >= limit) break; } } - Jorg Brown (jorg(AT)google.com), 
               Mar 05 2007
%Y A126098 Cf. A018892, A126097. Equals A117010(n) + 1.
%Y A126098 Sequence in context: A129301 A066523 A097212 this_sequence A018894 A056795 
               A141420
%Y A126098 Adjacent sequences: A126095 A126096 A126097 this_sequence A126099 A126100 
               A126101
%K A126098 nonn
%O A126098 1,2
%A A126098 N. J. A. Sloane (njas(AT)research.att.com), Mar 05 2007
%E A126098 More terms from Jorg Brown (jorg(AT)google.com) and T. D. Noe (noe(AT)sspectra.com), 
               Mar 05 2007
%E A126098 a(27) corrected by hupo001(AT)gmail.com, Jan 10 2008

    
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Last modified December 8 08:31 EST 2009. Contains 170430 sequences.


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