A196819 - OEIS

A196819

Decimal expansion of the least x>0 satisfying 1/(1+x^2)=4*cos(x).

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

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

OFFSET

1,2

LINKS

Table of n, a(n) for n=1..100.

EXAMPLE

x=1.4933195357382420192666761841798184096253499369741587866...

MATHEMATICA

Plot[{1/(1 + x^2), Cos[x], 2 Cos[x], 3 Cos[x], 4 Cos[x]}, {x, 0, 2}]

t = x /. FindRoot[1 == (1 + x^2) Cos[x], {x, 1, 1.5}, WorkingPrecision -> 100]

RealDigits[t] (* A196816 *)

t = x /. FindRoot[1 == 2 (1 + x^2) Cos[x], {x, 1, 1.6},

WorkingPrecision -> 100]

RealDigits[t] (* A196817 *)

t = x /. FindRoot[1 == 3 (1 + x^2) Cos[x], {x, 1, 1.6},

WorkingPrecision -> 100]

RealDigits[t] (* A196818 *)

t = x /. FindRoot[1 == 4 (1 + x^2) Cos[x], {x, 1, 1.6},

WorkingPrecision -> 100]

RealDigits[t] (* A196819 *)

t = x /. FindRoot[1 == 5 (1 + x^2) Cos[x], {x, 1, 1.6},

WorkingPrecision -> 100]

RealDigits[t] (* A196820 *)

t = x /. FindRoot[1 == 6 (1 + x^2) Cos[x], {x, 1, 1.6},

WorkingPrecision -> 100]

RealDigits[t] (* A196821 *)

CROSSREFS

Cf. A196914.

Sequence in context: A113970 A021957 A096301 * A296448 A217316 A159628

Adjacent sequences: A196816 A196817 A196818 * A196820 A196821 A196822

KEYWORD

nonn,cons

AUTHOR

Clark Kimberling, Oct 06 2011

STATUS

approved