A201531 Decimal expansion of x satisfying 2*x^2 + 3 = sec(x) and 0 < x < Pi.

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

Offset

1,2

Comments

See A201397 for a guide to related sequences. The Mathematica program includes a graph.

Links

Table of n, a(n) for n=1..99.

Example

x=1.42918273259701836782028842157379367447...

Mathematica

a = 2; c = 3;
f[x_] := a*x^2 + c; g[x_] := Sec[x]
Plot[{f[x], g[x]}, {x, 0, Pi/2}, {AxesOrigin -> {0, 0}}]
r = x /. FindRoot[f[x] == g[x], {x, 1.4, 1.5}, WorkingPrecision -> 110]
RealDigits[r]   (* A201531 *)

Crossrefs

Cf. A201397.

Sequence in context: A067721 A159899 A322550 * A021237 A115881 A180434

Adjacent sequences: A201528 A201529 A201530 * A201532 A201533 A201534

Keyword

nonn,cons

Author

Clark Kimberling, Dec 02 2011

Status

approved