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.
%I A135319 #14 Oct 31 2020 13:03:19 %S A135319 0,3,4,6,6,7,8,9,9,0,0,0,1,1,1,2,2,2,2,3,3,3,3,3,3,4,4,4,4,4,4,5,5,5, %T A135319 5,5,5,5,5,6,6,6,6,6,6,6,6,6,6,6,7,7,7,7,7,7,7,7,7,7,7,7,7,8,8,8,8,8, %U A135319 8,8,8,8,8,8,8,8,8,8,8,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9 %N A135319 a(n) is the first digit after the decimal point in the decimal expansion of log_10(n), i.e., of the Briggsian logarithm of n. %D A135319 Erwin Voellmy, Fünfstellige Logarithmen und Zahlentafeln, 15th edition, Orell Foessli Verlag, Zurich (1962). %H A135319 Wikipedia, <a href="http://en.wikipedia.org/wiki/Common_logarithm">Common logarithm</a> %F A135319 a(n) = floor(10*(log_10(n) - floor(log_10(n)))). %e A135319 a(6) = 7, because log_10(6) = 0.77815... %p A135319 A135319 := proc(n) floor(10*log[10](n)) mod 10 ; end: seq(A135319(n),n=1..80) ; # _R. J. Mathar_, Jan 11 2008 %K A135319 base,easy,nonn %O A135319 1,2 %A A135319 _Pahikkala Jussi_, Dec 06 2007, Jan 13 2008 %E A135319 More terms from _R. J. Mathar_ and _N. J. A. Sloane_, Jan 11 2008