A004083 - OEIS

A004083

Numbers k such that cos(k-1) <= 0 and cos(k) > 0.

5, 11, 18, 24, 30, 37, 43, 49, 55, 62, 68, 74, 81, 87, 93, 99, 106, 112, 118, 125, 131, 137, 143, 150, 156, 162, 169, 175, 181, 187, 194, 200, 206, 213, 219, 225, 231, 238, 244, 250, 257, 263, 269, 275, 282, 288, 294, 301, 307, 313, 319, 326, 332, 338, 345

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

Table of n, a(n) for n=1..55.

MATHEMATICA

Select[Range[0, 300], Cos[# - 1] <= 0 && Cos[#] > 0 &] (*T. D. Noe,Mar 21 2013 *)

SequencePosition[Table[If[Cos[n]>0, 1, 0], {n, 400}], {0, 1}][[All, 2]] (* Requires Mathematica version 10 or later *) (*Harvey P. Dale,Dec 12 2018 *)

PROG

(PARI) lista(m) = {for (i=0, m, if ((cos(i-1)<=0) && (cos(i) > 0), print1(i, "," )); ); } \\Michel Marcus,Mar 21 2013

CROSSREFS

Cf.A145005(except first term). -Sébastien Dumortier,Sep 30 2008

Sequence in context:A314272 A184822 A145005*A190365 A056000 A080566

Adjacent sequences:A004080 A004081 A004082*A004084 A004085 A004086

KEYWORD

nonn

AUTHOR

Clark Kimberling

EXTENSIONS

Term 1 removed (at the suggestion ofMichel Marcus) byT. D. Noe,Mar 21 2013

STATUS

approved