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A188039 Positions of 0 in A188038; complement of A188040. 3
2, 7, 12, 19, 24, 31, 36, 41, 48, 53, 60, 65, 70, 77, 82, 89, 94, 101, 106, 111, 118, 123, 130, 135, 140, 147, 152, 159, 164, 171, 176, 181, 188, 193, 200, 205, 210, 217, 222, 229, 234, 239, 246, 251, 258, 263, 270, 275, 280, 287, 292, 299, 304, 309, 316, 321, 328, 333, 340, 345, 350, 357, 362, 369, 374, 379, 386, 391, 398, 403, 408, 415, 420 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

See A188014.

There is (conjecturally) a connection a(1+n) = f(n) where f(n) = 3*n +2 +2*floor(n*sqrt 2) is defined in A120861. Tested numerically up to n=40000. - R. J. Mathar, Jul 22 2020

LINKS

G. C. Greubel, Table of n, a(n) for n = 1..10000

MAPLE

A188038 := proc(n)

    if n = 1 then

        1;

    else

        floor(n*sqrt(2))-floor((n-2)*sqrt(2))-2 ;

    end if;

end proc:

isA188039 := proc(n)

    if A188038(n) = 0 then

        true;

    else

        false;

    end if;

end proc:

A188039 := proc(n)

    option remember;

    if n = 1 then

        2;

    else

        for a from procname(n-1)+1 do

            if isA188039(a) then

                return a;

            end if;

        end do:

    end if;

end proc: # R. J. Mathar, Jul 22 2020

MATHEMATICA

r=2^(1/2)); k=2;

t=Table[Floor[n*r]-Floor[(n-k)*r]-Floor[k*r], {n, 1, 220}]   (*A188038*)

Flatten[Position[t, 0]]  (*A188039*)

Flatten[Position[t, 1]]  (*A188040*)

CROSSREFS

Cf. A188038, A188014, A188040.

Sequence in context: A099353 A297432 A299401 * A133459 A023669 A137401

Adjacent sequences:  A188036 A188037 A188038 * A188040 A188041 A188042

KEYWORD

nonn

AUTHOR

Clark Kimberling, Mar 19 2011

STATUS

approved

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Last modified May 17 22:15 EDT 2021. Contains 343992 sequences. (Running on oeis4.)