A027665 - OEIS

%I #14 Mar 05 2015 08:09:51

%S 0,30103,47712,60206,69897,77815,84510,90309,95424,100000,104139,

%T 107918,111394,114613,117609,120412,123045,125527,127875,130103,

%U 132222,134242,136173,138021,139794,141497,143136,144716,146240

%N a(n)/100000 gives log_10(n) to 5 places.

%C A tribute to 5-place logarithm tables which served many generations of students and technical people. - _Michael Somos_, Sep 21 2002

%C a(10*n) = a(n) + 100000, virtually. - _Reinhard Zumkeller_, Nov 12 2011

%H Reinhard Zumkeller, <a href="/A027665/b027665.txt">Table of n, a(n) for n = 1..10000</a>

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/CommonLogarithm.html">Common Logarithm</a>

%H Wikipedia, <a href="http://en.wikipedia.org/wiki/Common_logarithm">Common logarithm</a>

%H Wikipedia, <a href="http://en.wikipedia.org/wiki/Mathematical_table#Tables_of_logarithms">Tables of logarithms</a>

%p lprint(round(evalf(100000*log(n)/log(10))));

%o (PARI) a(n)=if(n<1,0,round(10^5*log(n)/log(10)))

%o (Haskell)

%o a027665 n = round $ 100000 * log (fromInteger n) / (log 10)

%o -- _Reinhard Zumkeller_, Nov 12 2011

%K nonn,base

%O 1,2

%A _N. J. A. Sloane_