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 A258782 #41 Sep 08 2022 08:46:12
%S A258782 0,0,1,3,5,7,9,12,15,18,22,25,29,33,36,40,44,48,53,57,61,65,70,74,79,
%T A258782 84,88,93,98,103,108,113,118,123,128,133,138,143,149,154,159,165,170,
%U A258782 175,181,186,192,197,203,209,214,220,226,231,237,243,249,254,260,266,272,278,284,290,296,302,308,314
%N A258782 Nearest integer to log_2(n!).
%F A258782 a(n) = round(log_2(n!)).
%F A258782 a(n) = A004257(A000142(n)). - _Michel Marcus_, Jun 10 2015
%F A258782 a(n) = round(Sum_{k=1..n} log_2(k)). - _Tom Edgar_, Jun 10 2015
%F A258782 a(n) is within 1 of n*(log(n)-1)/log(2) + log(n)/(2*log(2)) + log(sqrt(2*Pi))/log(2) for n >= 1. - _Robert Israel_, Jun 10 2015
%e A258782 a(6) = round(log_2(6!)) = round(9.49...) = 9.
%p A258782 seq(round(lnGAMMA(n+1)/ln(2)),n=0..100); # _Robert Israel_, Jun 10 2015
%t A258782 Round[Log[2, Range[0, 100]! ]] (* _Giovanni Resta_, Jun 10 2015 *)
%o A258782 (MATLAB) for i = 1:20 { disp(round(log2(factorial(i)))) } end
%o A258782 (PARI) a(n) = round(log(n!)/log(2)); \\ _Michel Marcus_, Jun 10 2015
%o A258782 (PARI) a(n)=round(lngamma(n+1)/log(2)) \\ _Charles R Greathouse IV_, Jun 10 2015
%o A258782 (Magma) [Round(LogGamma(n+1)/Log(2)): n in [0..70]]; // _Bruno Berselli_, Jun 23 2015
%o A258782 (Sage) [round(log_gamma(n+1)/log2) for n in (0..70)] # _Bruno Berselli_, Jun 23 2015
%Y A258782 Cf. A025201, A067850.
%K A258782 nonn,easy
%O A258782 0,4
%A A258782 _Eli Sadoff_, Jun 10 2015