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A263390 a(3n) = n, otherwise a(n) = a(floor(2n/3)). 1
0, 0, 0, 1, 0, 1, 2, 0, 1, 3, 2, 0, 4, 1, 3, 5, 2, 0, 6, 4, 1, 7, 3, 5, 8, 2, 0, 9, 6, 4, 10, 1, 7, 11, 3, 5, 12, 8, 2, 13, 0, 9, 14, 6, 4, 15, 10, 1, 16, 7, 11, 17, 3, 5, 18, 12, 8, 19, 2, 13, 20, 0, 9, 21, 14, 6, 22, 4, 15, 23, 10, 1, 24, 16, 7, 25 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,7

COMMENTS

This sequence is the unique fixed point of the function (a(0), a(1), a(2), ...) |--> (0, a(0), a(1), 1, a(2), a(3), 2, a(4), a(5), ...) which interleaves the nonnegative integers with pairs of elements of a sequence.

Compare with A025480, the unique fixed point of the function (a(0), a(1), a(2), ...) |--> (0, a(0), 1, a(1), 2, a(2), ...) which interleaves the nonnegative integers between the elements of a sequence.

These are the nim-values for heaps of n beans in the game where you're allowed to take up to one-third of the beans in a heap.

LINKS

Table of n, a(n) for n=0..75.

FORMULA

a(n) = A163491(n+1) - 1. - Peter Munn, Nov 22 2020

PROG

(PARI) a(n)=if(n%3, a(2*n\3), n/3) \\ Charles R Greathouse IV, Apr 30 2016

CROSSREFS

Comparable sequences: A025480, A163491.

Ordinal transform: A087088.

Sequence in context: A338526 A182703 A307226 * A231354 A197119 A124377

Adjacent sequences:  A263387 A263388 A263389 * A263391 A263392 A263393

KEYWORD

nonn,easy

AUTHOR

Lee A. Newberg, Apr 27 2016

STATUS

approved

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Last modified April 14 07:59 EDT 2021. Contains 342946 sequences. (Running on oeis4.)