A088543 - OEIS

The OEIS is supported by the many generous donors to the OEIS Foundation.

A088543

Decimal expansion of sqrt(15)/2.

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, 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, 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

(list; constant; graph; refs; listen; history; text; internal format)

OFFSET

1,2

COMMENTS

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.

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

LINKS

Daniel Starodubtsev, Table of n, a(n) for n = 1..10000

Eric Weisstein's World of Mathematics, Exradius.

Index entries for algebraic numbers, degree 2

FORMULA

sqrt(15)/2 = A010472/2 = A140249/3. - Rick L. Shepherd, May 14 2008

EXAMPLE

1.93649167310370844258963269989119980541646085264579541329378688305674154596...

MATHEMATICA

First[RealDigits[Sqrt[15]/2, 10, 100]] (* Paolo Xausa, Jun 18 2024 *)

CROSSREFS

Cf. A010527.