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A088306 Integers n with tan n > |n|, ordered by |n|. 8
1, -2, -11, -33, -52174, 260515, -573204, 37362253, -42781604, 122925461, 534483448, 3083975227, 902209779836, -2685575996367, -65398140378926, 74357078147863, 214112296674652, 642336890023956, -5920787228742393, -12055686754159438, 18190586279576483, -48436859313312404 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
Name was "Positive integers n with |tan n| > n." before signs were added. The sign here shows whether tan(|n|) is positive or negative.
That this sequence is infinite was proved by Bellamy, Lagarias and Lazebnik. It seems not to be known whether there are infinitely many n with tan n > n.
At approximately 2.37e154, there is a value of n which has tan(n)/n > 556. - Phil Carmody, Mar 04 2007 [This is index 214 in the b-file.]
As n increases, log(|a(n)|)/n seems to approach Pi/2; this is similar to what would be expected if an integer sequence were created by drawing many random numbers independently from a uniform distribution on the interval [-Pi/2,+Pi/2] and including in the sequence only those integers j for which the j-th random number x_j happened to satisfy |x_j| < 1/j (and applying to j the sign of x_j). - Jon E. Schoenfield, Aug 19 2014; updated Nov 07 2014 to reflect the change in the sequence's Name)
LINKS
D. Bellamy, J. C. Lagarias and F. Lazebnik, Proposed problem: large values of Tan n
Jon E. Schoenfield, Magma program
MAPLE
a:=proc(n) if abs(evalf(tan(n)))>n then n else fi end: seq(a(n), n=1..100000); # Emeric Deutsch, Dec 18 2004
MATHEMATICA
Select[Range[600000], Abs[Tan[#]]>#&] (* Harvey P. Dale, Nov 30 2012 *)
PROG
(PARI) is(n)=tan(n)>abs(n) \\ Charles R Greathouse IV, Nov 07 2014
CROSSREFS
Cf. A249836 (subsequence of positive terms).
Sequence in context: A034427 A056368 A056359 * A100109 A328152 A209033
KEYWORD
sign
AUTHOR
Paul Boddington, Nov 05 2003
EXTENSIONS
More terms from Jon E. Schoenfield, Aug 17 2014
Signs added and other edits by Franklin T. Adams-Watters, Sep 09 2014
STATUS
approved

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Last modified April 23 06:04 EDT 2024. Contains 371906 sequences. (Running on oeis4.)