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A053246
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First differences of chowla(n).
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2
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0, 0, 2, -2, 5, -5, 6, -3, 4, -7, 15, -15, 9, -1, 6, -14, 20, -20, 21, -11, 3, -13, 35, -30, 10, -3, 15, -27, 41, -41, 30, -16, 5, -7, 42, -54, 21, -5, 33, -49, 53, -53, 39, -7, -7, -25, 75, -68, 35, -22, 25, -45, 65, -49, 47, -41, 9, -31, 107, -107, 33, 7, 22, -44, 59, -77, 57, -31
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OFFSET
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1,3
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COMMENTS
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Second differences give A053223, for n>1.
If the first term is changed to 1, this is also the first differences of A001065. - N. J. A. Sloane, Jan 17 2023
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LINKS
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FORMULA
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MAPLE
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with(numtheory): seq( sigma(i+1) - sigma(i) - 1, i=2..100); # for n>1
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MATHEMATICA
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Chowlan[n_] := If[n == 1, 0, DivisorSigma[1, n] - n - 1]; Table[Chowlan[n + 1] - Chowlan[n], {n, 1, 100}] (* G. C. Greubel, Sep 03 2018 *)
Differences[Join[{0}, Table[DivisorSigma[1, n]-n-1, {n, 2, 100}]]] (* Harvey P. Dale, Dec 19 2022 *)
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PROG
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(Magma) [0] cat [DivisorSigma(1, n+1) - DivisorSigma(1, n) - 1: n in [2..100]]; // G. C. Greubel, Sep 03 2018
(PARI) concat([0], vector(100, n, n++; sigma(n+1) - sigma(n) -1)) \\ G. C. Greubel, Sep 03 2018
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CROSSREFS
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KEYWORD
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sign
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AUTHOR
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STATUS
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approved
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