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A038555 Derivative of n in base 3. 1
0, 0, 0, 1, 2, 0, 2, 0, 1, 3, 4, 5, 7, 8, 6, 2, 0, 1, 6, 7, 8, 1, 2, 0, 5, 3, 4, 9, 10, 11, 13, 14, 12, 17, 15, 16, 21, 22, 23, 25, 26, 24, 20, 18, 19, 6, 7, 8, 1, 2, 0, 5, 3, 4, 18, 19, 20, 22, 23, 21, 26, 24, 25, 3, 4, 5, 7, 8, 6, 2, 0, 1, 15, 16, 17, 10, 11, 9, 14, 12, 13, 27, 28, 29 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,5

LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 0..10000

FORMULA

Write n in ternary, replace each pair of adjacent digits by their modulo 3 sum.

EXAMPLE

15 = 120 in ternary, derivative is 02 = 2, so a(15)=2.

PROG

(Haskell)

a038555 n = foldr (\d v -> v * 3 + d) 0 $

   zipWith (\x y -> (x + y) `mod` 3) ts $ tail ts

   where ts = a030341_row n

-- Reinhard Zumkeller, May 26 2013

(J) ab3 =: 3&#.^:_1

sp =: 2&(+/\)"1

> (3 | sp)&.ab3&.> ; / i. 100 NB. Stephen Makdisi, May 26 2018

CROSSREFS

Cf. A038554.

Cf. A030341.

Sequence in context: A323226 A307197 A328949 * A138108 A158777 A039970

Adjacent sequences:  A038552 A038553 A038554 * A038556 A038557 A038558

KEYWORD

nonn,nice,easy,base

AUTHOR

N. J. A. Sloane

EXTENSIONS

More terms from Erich Friedman

Formula corrected by Reinhard Zumkeller, May 26 2013

STATUS

approved

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Last modified August 6 22:01 EDT 2020. Contains 336256 sequences. (Running on oeis4.)