A088543 - OEIS

%I #12 Jun 18 2024 03:25:38

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

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

%U 4,1,5,4,5,9,6,8,4,8,9,5,1,6,7,5,9,6,4,3,6,8,8,4,2,9,3,3,6,7,5,8,9,5,8,1,5

%N Decimal expansion of sqrt(15)/2.

%C This is the ratio of the base of an isosceles triangle to its height when the other two sides are each equal to twice the base.

%C Exradius opposite the side of length 3 of the obtuse scalene triangle with sides of lengths 2, 3 and 4, the scalene triangle with least integer side lengths. See formulas in the Weisstein link. - _Rick L. Shepherd_, May 14 2008

%H Daniel Starodubtsev, <a href="/A088543/b088543.txt">Table of n, a(n) for n = 1..10000</a>

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

%H <a href="/index/Al#algebraic_02">Index entries for algebraic numbers, degree 2</a>

%F sqrt(15)/2 = A010472/2 = A140249/3. - _Rick L. Shepherd_, May 14 2008

%e 1.93649167310370844258963269989119980541646085264579541329378688305674154596...

%t First[RealDigits[Sqrt[15]/2, 10, 100]] (* _Paolo Xausa_, Jun 18 2024 *)

%Y Cf. A010527.

%Y Cf. A140239, A140246, A140247, A140248, A140249, A010472.

%K cons,nonn

%O 1,2

%A Christopher M. Tomaszewski (cmt1288(AT)comcast.net), Nov 16 2003

%E More terms from _Rick L. Shepherd_, May 14 2008