A369273 Nonnegative numbers k satisfying sin(k) < sin(k+1) < sin(k+2).

0, 5, 6, 11, 12, 17, 18, 24, 25, 30, 31, 36, 37, 42, 43, 44, 49, 50, 55, 56, 61, 62, 68, 69, 74, 75, 80, 81, 86, 87, 88, 93, 94, 99, 100, 105, 106, 112, 113, 118, 119, 124, 125, 130, 131, 132, 137, 138, 143, 144, 149, 150, 156, 157, 162, 163, 168, 169, 174, 175, 181, 182, 187, 188, 193, 194

Offset

1,2

Comments

Subsequence of terms in A026309: The smaller of two consecutive terms there.

The terms A246389(.)-2 almost match the terms here; the exceptions are terms 178, 220, 266, 310, 555, 599, ... in A246389 where the associates 176, 218, 264, 308, ... are not in this sequence. - Hugo Pfoertner, Jan 18 2024

Links

Table of n, a(n) for n=1..66.

Maple

isA369273 := proc(k)
    local s ;
    s := [seq(evalf(sin(k+i)), i=0..2)] ;
    if s[1] < s[2] and s[2] < s[3] then
        true;
    else
        false;
    end if;
end proc:
A369273 := proc(n)
    option remember ;
    if n = 1 then
        0;
    else
        for a from procname(n-1)+1 do
            if isA369273(a) then
                return a;
            end if;
        end do:
    end if;
end proc:
seq(A369273(n), n=1..100) ;

Mathematica

Select[Range[0, 194], Sin[#]<Sin[#+1]<Sin[#+2]&] (* James C. McMahon, Jan 22 2024 *)

Crossrefs

Cf. A026309, A369274, A369275.

Sequence in context: A215033 A047264 A343405 * A277095 A332482 A190895

Adjacent sequences: A369270 A369271 A369272 * A369274 A369275 A369276

Keyword

nonn,easy

Author

R. J. Mathar, Jan 18 2024

Status

approved