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A065364
Alternating sum of balanced ternary digits in n. Replace 3^k with (-1)^k in balanced ternary expansion of n.
5
1, -2, -1, 0, 1, 2, 3, 0, 1, 2, -1, 0, 1, -2, -1, 0, -3, -2, -1, -4, -3, -2, -1, 0, 1, -2, -1, 0, -3, -2, -1, 0, 1, 2, -1, 0, 1, -2, -1, 0, 1, 2, 3, 0, 1, 2, -1, 0, 1, 2, 3, 4, 1, 2, 3, 0, 1, 2, 3, 4, 5, 2, 3, 4, 1, 2, 3, 0, 1, 2, -1, 0, 1, -2, -1, 0, 1, 2, 3, 0, 1, 2, -1, 0, 1, 2, 3, 4, 1, 2, 3, 0, 1, 2, -1, 0, 1, -2, -1, 0, -3, -2, -1, 0
OFFSET
1,2
COMMENTS
Notation: (3)<n>(-1).
LINKS
EXAMPLE
5 = +1(9)-1(3)-1(1) -> +1(+1)-1(-1)-1(+1) = +1 = a(5).
MATHEMATICA
Array[Total@ MapIndexed[#1 (2 Mod[First[#2], 2] - 1) &, Reverse@ #] &[Prepend[IntegerDigits[#, 3], 0] //. {a___, b_, 2, c___} :> {a, b + 1, -1, c}] &, 104] (* Michael De Vlieger, Jun 27 2020 *)
CROSSREFS
KEYWORD
base,easy,sign
AUTHOR
Marc LeBrun, Oct 31 2001
STATUS
approved