A195456 - OEIS

%I #10 Dec 24 2017 09:26:00

%S 1,0,3,9,0,8,1,4,7,6,5,9,6,9,8,9,2,3,0,5,5,0,3,1,1,6,2,1,1,2,9,7,8,9,

%T 1,0,3,0,4,1,8,7,9,6,3,9,5,4,0,3,7,6,8,1,8,9,3,8,7,8,7,0,8,0,5,9,7,8,

%U 5,4,1,3,5,3,1,5,9,9,7,9,0,3,1,4,5,6,9,5,2,5,5,6,5,2,3,6,1,1,4,7

%N Decimal expansion of shortest length, (C), of segment from side CA through centroid to side CB in right triangle ABC with sidelengths (a,b,c)=(sqrt(2),sqrt(3),sqrt(5)).

%C See A195304 for definitions and a general discussion.

%H G. C. Greubel, <a href="/A195456/b195456.txt">Table of n, a(n) for n = 1..10000</a>

%e (C)=1.03908147659698923055031162112978910304...

%t a = Sqrt[2]; b = Sqrt[3]; h = 2 a/3; k = b/3;

%t f[t_] := (t - a)^2 + ((t - a)^2) ((a*k - b*t)/(a*h - a*t))^2

%t s = NSolve[D[f[t], t] == 0, t, 150]

%t f1 = (f[t])^(1/2) /. Part[s, 4]

%t RealDigits[%, 10, 100] (* (A) A195454 *)

%t f[t_] := (t - a)^2 + ((t - a)^2) (k/(h - t))^2

%t s = NSolve[D[f[t], t] == 0, t, 150]

%t f2 = (f[t])^(1/2) /. Part[s, 4]

%t RealDigits[%, 10, 100] (* (B) A195455 *)

%t f[t_] := (b*t/a)^2 + ((b*t/a)^2) ((a*h - a*t)/(b*t - a*k))^2

%t s = NSolve[D[f[t], t] == 0, t, 150]

%t f3 = (f[t])^(1/2) /. Part[s, 1]

%t RealDigits[%, 10, 100] (* (C) A195456 *)

%t c = Sqrt[a^2 + b^2]; (f1 + f2 + f3)/(a + b + c)

%t RealDigits[%, 10, 100] (* Philo(ABC,G) A195457 *)

%Y Cf. A195304, A195454, A195455, A195457.

%K nonn,cons

%O 1,3

%A _Clark Kimberling_, Sep 19 2011