

A242399


Write n and 3n in ternary representation and add all trits modulo 3.


8



0, 4, 8, 12, 16, 11, 24, 19, 23, 36, 40, 44, 48, 52, 47, 33, 28, 32, 72, 76, 80, 57, 61, 56, 69, 64, 68, 108, 112, 116, 120, 124, 119, 132, 127, 131, 144, 148, 152, 156, 160, 155, 141, 136, 140, 99, 103, 107, 84, 88, 83, 96, 91, 95, 216, 220, 224, 228, 232
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OFFSET

0,2


LINKS

Eric Weisstein's World of Mathematics, Ternary.


FORMULA

a(n) <= 4*n; a(m) = 4*m iff m is a term of A242407.


EXAMPLE

n = 25, 3*n = 75:
. add trits 
. modulo 3 2101 = A007089(64), hence a(25) = 64.


PROG

(Haskell)
a242399 n = foldr (\t v > 3 * v + t) 0 $
map (flip mod 3) $ zipWith (+) ([0] ++ ts) (ts ++ [0])
where ts = a030341_row n


CROSSREFS



KEYWORD

nonn,base


AUTHOR



STATUS

approved



