%I #13 Sep 08 2022 08:45:05
%S 0,0,2,2,4,1,0,7,7,3,3,6,4,10,9,1,15,2,8,10,14,6,4,7,3,3,2,2,7,26,3,
%T 30,3,31,9,29,23,12,29,3,0,12,1,11,4,13,22,17,24,33,40,34,48,27,15,5,
%U 33,33,51,48,42,46,47,38,35,30,27,1,51,52,28,25,13,30,51,14,39,12,9,58,33
%N Factorial expansion of log(Pi/2) = sum n>0 a(n)/n!.
%H G. C. Greubel, <a href="/A068449/b068449.txt">Table of n, a(n) for n = 1..10000</a>
%t Table[If[n == 1, Floor[Log[Pi/2]], Floor[n!*Log[Pi/2]] - n*Floor[(n - 1)!*Log[Pi/2]]], {n, 1, 50}] (* _G. C. Greubel_, Mar 21 2018 *)
%o (PARI) for(n=1,30, print1(if(n==1, floor(log(Pi/2)), floor(n!*log(Pi/2)) - n*floor((n-1)!*log(Pi/2))), ", ")) \\ _G. C. Greubel_, Mar 21 2018
%o (Magma) R:= RealField(); [Floor(Log(Pi(R)/2))] cat [Floor(Factorial(n)*Log(Pi(R)/2)) - n*Floor(Factorial((n-1))* Log(Pi(R)/2)) : n in [2..30]]; // _G. C. Greubel_, Mar 21 2018
%Y Cf. A007514, A094642 (decimal expansion).
%K easy,nonn
%O 1,3
%A _Benoit Cloitre_, Mar 10 2002