A188039 Positions of 0 in A188038; complement of A188040.

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

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