A065364 Alternating sum of balanced ternary digits in n. Replace 3^k with (-1)^k in balanced ternary expansion of n.

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

Author

Marc LeBrun, Oct 31 2001

Keywords

• base
• easy
• sign

Comments

Notation: (3)(-1).

Examples

			5 = +1(9)-1(3)-1(1) -> +1(+1)-1(-1)-1(+1) = +1 = a(5).
		

Links

• Michael De Vlieger, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A059095, A065363, A065368.

Programs

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 *)