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 A179529 Number of terms of A083207 in 12 consecutive numbers. 7
 2, 2, 2, 2, 2, 2, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 4, 4, 3, 3, 3, 3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 2, 2, 3, 3, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 3, 3, 3, 3, 3, 3, 3, 3, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 3 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS a(n) = SUM(A179527(k): n <= k < n+12); F. Buss and T. D. Noe conjectured a(n) > 0; this is correct (proof by R. Gerbicz); a(n+1) = A179528(n+12) - A179528(n); a(A179530(n)) = n and a(m) <> n for m < A179530(n). LINKS R. Zumkeller, Table of n, a(n) for n = 1..10000 Peter Luschny, Zumkeller Numbers MATHEMATICA ZumkellerQ[n_] := Module[{d = Divisors[n], t, ds, x}, ds = Total[d]; If[Mod[ds, 2] > 0, False, t = CoefficientList[Product[1 + x^i, {i, d}], x]; t[[1 + ds/2]] > 0]]; a[n_] := Sum[Boole[ZumkellerQ[k]], {k, n, n + 11}]; Array[a, 105] (* Jean-François Alcover, Apr 30 2017, after T. D. Noe *) CROSSREFS Sequence in context: A085297 A080972 A037814 * A118668 A273429 A273915 Adjacent sequences: A179526 A179527 A179528 * A179530 A179531 A179532 KEYWORD nonn AUTHOR Reinhard Zumkeller, Jul 19 2010 STATUS approved

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Last modified June 22 14:15 EDT 2024. Contains 373587 sequences. (Running on oeis4.)