login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A246415 Positive integers k satisfying csc(k) < csc(k+1) < csc(k+2) > csc(k+3). 3

%I

%S 22,66,110,154,177,221,265,309,355,399,443,487,554,598,642,686,732,

%T 776,820,864,887,931,975,1019,1065,1109,1153,1197,1264,1308,1352,1396,

%U 1442,1486,1530,1574,1597,1641,1685,1729,1775,1819,1863,1907,1974,2018,2062

%N Positive integers k satisfying csc(k) < csc(k+1) < csc(k+2) > csc(k+3).

%C A246413, A246414, and this sequence partition the positive integers.

%H Clark Kimberling, <a href="/A246415/b246415.txt">Table of n, a(n) for n = 1..1000</a>

%t z = 200;

%t f[x_] := f[x] = Csc[x];

%t Select[Range[1, z], f[#] > f[# + 1] &] (* A246413 *)

%t Select[Range[1, z], f[#] < f[# + 1] > f[# + 2] &] (* A246414 *)

%t Select[Range[1, z], f[#] < f[# + 1] < f[# + 2] > f[# + 3] &] (* A246415 *)

%o (PARI) is(n) = (1/sin(n)) < (1/sin(n+1)) && (1/sin(n+1)) < (1/sin(n+2)) && (1/sin(n+2)) > (1/sin(n+3)) \\ _Felix Fröhlich_, Jan 02 2018

%Y Cf. A246413, A246414.

%K nonn,easy

%O 1,1

%A _Clark Kimberling_, Aug 25 2014

%E Name corrected by _David Gross_, Jan 02 2018

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified June 19 23:01 EDT 2019. Contains 324222 sequences. (Running on oeis4.)