A196607 Decimal expansion of the least x>0 satisfying sec(x)=6x.

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

Offset

0,2

Links

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

Example

x=0.169077647398015149995295367672627810742134076969653717056...

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 *)

Prog

(PARI) solve(x=0, 1, 6*x*cos(x)-1) \\ Charles R Greathouse IV, Aug 23 2021

Crossrefs

Sequence in context: A195102 A020792 A242760 * A200015 A298517 A199451

Adjacent sequences: A196604 A196605 A196606 * A196608 A196609 A196610

Keyword

nonn,cons

Author

Clark Kimberling, Oct 04 2011

Status

approved