A073792 - OEIS

A073792

Replace 5^k with (-5)^k in base 5 expansion of n.

0, 1, 2, 3, 4, -5, -4, -3, -2, -1, -10, -9, -8, -7, -6, -15, -14, -13, -12, -11, -20, -19, -18, -17, -16, 25, 26, 27, 28, 29, 20, 21, 22, 23, 24, 15, 16, 17, 18, 19, 10, 11, 12, 13, 14, 5, 6, 7, 8, 9, 50, 51, 52, 53, 54, 45, 46, 47, 48, 49, 40, 41, 42, 43, 44, 35, 36, 37, 38, 39, 30, 31, 32, 33, 34

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OFFSET

0,3

COMMENTS

Base 5 representation for n converted from base -5 to base 10.

LINKS

Table of n, a(n) for n=0..74.

Dana G. Korssjoen, Biyao Li, Stefan Steinerberger, Raghavendra Tripathi, and Ruimin Zhang, Finding structure in sequences of real numbers via graph theory: a problem list, arXiv:2012.04625 [math.CO], 2020-2021.

FORMULA

a(5*k+m) = -5*a(k)+m for 0 <= m < 5. - Chai Wah Wu, Jan 16 2020

MATHEMATICA

f[n_Integer, b_Integer] := Block[{l = IntegerDigits[n]}, Sum[l[[ -i]]*(-b)^(i - 1), {i, 1, Length[l]}]]; a = Table[ FromDigits[ IntegerDigits[n, 5]], {n, 0, 80}]; b = {}; Do[b = Append[b, f[a[[n]], 5]], {n, 1, 80}]; b

CROSSREFS

Cf. A007091, A073786, A053985, A065369, A073791, A073793, A073794, A073795, A073796 & A073835.

Sequence in context: A181975 A062406 A271800 * A017870 A017860 A328765

Adjacent sequences: A073789 A073790 A073791 * A073793 A073794 A073795

KEYWORD

base,easy,sign

AUTHOR

Robert G. Wilson v, Aug 12 2002

STATUS

approved