A196612 Decimal expansion of the least x>0 satisfying 2*sec(x)=x.

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

Offset

1,1

Links

Table of n, a(n) for n=1..101.

Example

x=5.11418218785581587491977554892680077350563...

Mathematica

Plot[{1/x, 2/x, 3/x, 4/x, Cos[x]}, {x, 0, 2 Pi}]
t = x /. FindRoot[1/x == Cos[x], {x, 4, 7}, WorkingPrecision -> 100]
RealDigits[t]  (* A133868 *)
t = x /. FindRoot[2/x == Cos[x], {x, 4, 7}, WorkingPrecision -> 100]
RealDigits[t]  (* A196612 *)
t = x /. FindRoot[3/x == Cos[x], {x, 4, 7}, WorkingPrecision -> 100]
RealDigits[t]  (* A196613 *)
t = x /. FindRoot[4/x == Cos[x], {x, 4, 7}, WorkingPrecision -> 100]
RealDigits[t]  (* A196614 *)
t = x /. FindRoot[5/x == Cos[x], {x, 4, 7}, WorkingPrecision -> 100]
RealDigits[t]    (* A196615 *)
t = x /. FindRoot[6/x == Cos[x], {x, 4, 7}, WorkingPrecision -> 100]
RealDigits[t]   (* A196616 *)

Crossrefs

Cf. A196604.

Sequence in context: A154567 A260210 A139391 * A110635 A179773 A244977

Adjacent sequences: A196609 A196610 A196611 * A196613 A196614 A196615

Keyword

nonn,cons

Author

Clark Kimberling, Oct 04 2011

Status

approved