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A189674 Partial sums of A189673. 2
0, 1, 1, 2, 3, 3, 3, 4, 4, 5, 6, 6, 7, 8, 8, 8, 9, 9, 9, 10, 10, 11, 12, 12, 12, 13, 13, 14, 15, 15, 16, 17, 17, 17, 18, 18, 19, 20, 20, 21, 22, 22, 22, 23, 23, 23, 24, 24, 25, 26, 26, 26, 27, 27, 27, 28, 28, 29, 30, 30, 30, 31, 31, 32, 33, 33, 34, 35, 35, 35, 36, 36, 36, 37, 37, 38, 39, 39, 39, 40, 40 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,4

COMMENTS

See A189673.

LINKS

Table of n, a(n) for n=1..81.

Kevin Ryde, Iterations of the Terdragon Curve, see index "TurnsL", with a(n) = TurnsL(n-1).

FORMULA

a(n) = a(floor((n+2)/3)) + floor((n+1)/3), where a(1)=0.

MATHEMATICA

(See A189673.)

PROG

(PARI) a(n) = n--; (n + vecsum(digits(n, 3)%2))/2; \\ Kevin Ryde, Apr 23 2021

CROSSREFS

Cf. A189673.

Sequence in context: A296021 A267097 A194198 * A156250 A029108 A181550

Adjacent sequences:  A189671 A189672 A189673 * A189675 A189676 A189677

KEYWORD

nonn

AUTHOR

Clark Kimberling, Apr 25 2011

STATUS

approved

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Last modified October 21 15:46 EDT 2021. Contains 348155 sequences. (Running on oeis4.)