A189672 - OEIS

A189672

Partial sums of A080846.

0, 1, 1, 1, 2, 3, 3, 4, 4, 4, 5, 5, 5, 6, 7, 7, 8, 9, 9, 10, 10, 10, 11, 12, 12, 13, 13, 13, 14, 14, 14, 15, 16, 16, 17, 17, 17, 18, 18, 18, 19, 20, 20, 21, 22, 22, 23, 23, 23, 24, 25, 25, 26, 27, 27, 28, 28, 28, 29, 30, 30, 31, 31, 31, 32, 32, 32, 33, 34, 34, 35, 36, 36, 37, 37, 37, 38, 39, 39, 40

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OFFSET

1,5

COMMENTS

Almost identical to A189641.

LINKS

Table of n, a(n) for n=1..80.

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

FORMULA

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

MATHEMATICA

t = Nest[Flatten[# /. {0->{0, 1, 0}, 1->{0, 1, 1}}] &, {0}, 5] (*A080846*)