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A297239
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Total variation of base-13 digits of n; see Comments.
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4
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0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 2, 1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 3, 2, 1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 4, 3, 2, 1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 5, 4, 3, 2, 1, 0, 1, 2, 3, 4, 5, 6, 7, 6, 5, 4, 3, 2, 1, 0, 1
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OFFSET
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1,16
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COMMENTS
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Suppose that a number n has base-b digits b(m), b(m-1), ..., b(0). The base-b down-variation of n is the sum DV(n,b) of all d(i)-d(i-1) for which d(i) > d(i-1); the base-b up-variation of n is the sum UV(n,b) of all d(k-1)-d(k) for which d(k) < d(k-1). The total base-b variation of n is the sum TV(n,b) = DV(n,b) + UV(n,b). See A297330 for a guide to related sequences and partitions of the natural numbers:
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LINKS
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EXAMPLE
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2^20 in base 13: 2, 10, 9, 3, 7, 9; here, DV = 12 and UV = 9, so that a(2^20) = 21.
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MATHEMATICA
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b = 13; z = 120; t = Table[Total@Flatten@Map[Abs@Differences@# &, Partition[IntegerDigits[n, b], 2, 1]], {n, z}] (* cf. Michael De Vlieger, e.g. A037834 *)
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CROSSREFS
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KEYWORD
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nonn,base,easy
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AUTHOR
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STATUS
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approved
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