A201411 Decimal expansion of greatest x satisfying 4*x^2 = sec(x) and 0 < x < Pi.

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

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

least:  0.53986108391277844363067373273228071480624...
greatest: 1.451925722123287999446946604502079960054...

Mathematica

a = 4; c = 0;
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, .5, .6}, WorkingPrecision -> 110]
RealDigits[r]    (* A201410 *)
r = x /. FindRoot[f[x] == g[x], {x, 1.4, 1.5}, WorkingPrecision -> 110]
RealDigits[r]    (* A201411 *)

Crossrefs

Cf. A201397.

Sequence in context: A199384 A178233 A271356 * A353313 A206282 A378347

Adjacent sequences: A201408 A201409 A201410 * A201412 A201413 A201414

Keyword

nonn,cons

Author

Clark Kimberling, Dec 01 2011

Status

approved