A196605 Decimal expansion of the least x>0 satisfying sec(x)=4x.

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

Offset

0,1

Links

Table of n, a(n) for n=0..99.

Example

x=0.25859858225418949030448261956152028133855...

Mathematica

Plot[{1/x, Cos[x], 2 Cos[x], 3*Cos[x], 4 Cos[x]}, {x, 0, 2 Pi}]
t = x /. FindRoot[1/x == Cos[x], {x, .1, 5}, WorkingPrecision -> 100]
RealDigits[t]  (* A133868 *)
t = x /. FindRoot[1/x == 2 Cos[x], {x, .5, .7}, WorkingPrecision -> 100]
RealDigits[t]  (* A196603 *)
t = x /. FindRoot[1/x == 3 Cos[x], {x, .3, .4}, WorkingPrecision -> 100]
RealDigits[t]  (* A196604 *)
t = x /. FindRoot[1/x == 4 Cos[x], {x, .1, .3}, WorkingPrecision -> 100]
RealDigits[t]  (* A196605 *)
t = x /. FindRoot[1/x == 5 Cos[x], {x, .15, .23}, WorkingPrecision -> 100]
RealDigits[t]  (* A196606 *)
t = x /. FindRoot[1/x == 6 Cos[x], {x, .1, .2}, WorkingPrecision -> 100]
RealDigits[t]  (* A196607 *)

Crossrefs

Cf. A295255.

Sequence in context: A062089 A011201 A201772 * A182243 A360898 A118119

Adjacent sequences: A196602 A196603 A196604 * A196606 A196607 A196608

Keyword

nonn,cons

Author

Clark Kimberling, Oct 04 2011

Status

approved