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%I A093082 #16 Dec 15 2017 17:36:34
%S A093082 1,1,8,2,334,2450,688,958,60676,151,239478914,1718557,43588850341,
%T A093082 44525,3435544097,128202996855,166046498,468640744,9748065626452,
%U A093082 2406214305714,54782975386,249195119225246375,20940713346,57388133232314021954,9869596698791300782235,187739128455384480612259907,184395236716104
%N A093082 Number of steps to factor n!-1 using Fermat's factorization method.
%H A093082 Harry J. Smith and Max Alekseyev, <a href="/A093082/b093082.txt">Table of n, a(n) for n = 2..135</a>
%F A093082 For n>2, a(n) = (d + (m)/d)/2 - floor(sqrt(m)), where m=n!-1 and d is the smallest divisor of m such that d >=sqrt(m). - _Max Alekseyev_, Apr 13 2009
%o A093082 (PARI) { a(n) = my(m); if(n==2,return(1)); m=n!-1; fordiv(m,d, if(d*d>=m,return((d+m\d)\2-sqrtint(m));); ) } /* _Max Alekseyev_, Apr 13 2009 */
%Y A093082 Cf. A078753.
%K A093082 hard,nonn
%O A093082 2,3
%A A093082 _Jason Earls_, May 09 2004
%E A093082 Extended by _Max Alekseyev_, Apr 13 2009
%E A093082 a(60)-a(135) from _Max Alekseyev_, Dec 29 2015

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