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A188090 [nr+kr]-[nr]-[kr], where r=sqrt(3), k=5, [ ]=floor. 3
1, 1, 0, 1, 1, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 0, 0, 1, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET

1

COMMENTS

See A187950.

LINKS

Chai Wah Wu, Table of n, a(n) for n = 1..10000

FORMULA

a(n)=[nr+5r]-[nr]-[5r], where r=sqrt(3).

MATHEMATICA

r=3^(1/2); k=5;

seqA=Table[Floor[n*r+k*r]-Floor[n*r]-Floor[k*r], {n, 1, 220}]   (* A188090 *)

Flatten[Position[seqA, 0] ]   (* A188091 *)

Flatten[Position[seqA, 1] ]   (* A188092 *)

PROG

(Python)

from gmpy2 import isqrt

def A188090(n):

    return int(isqrt(3*(n+5)**2)-isqrt(3*n**2)) - 8 # Chai Wah Wu, Oct 08 2016

CROSSREFS

Cf. A187950, A188091, A188092.

Sequence in context: A030324 A014174 A014339 * A004547 A285358 A230603

Adjacent sequences:  A188087 A188088 A188089 * A188091 A188092 A188093

KEYWORD

nonn

AUTHOR

Clark Kimberling, Mar 20 2011

STATUS

approved

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Last modified May 23 10:05 EDT 2022. Contains 353975 sequences. (Running on oeis4.)