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 A179528 Number of terms of A083207 that are not greater than n. 4

%I #9 Apr 30 2017 22:37:10

%S 0,0,0,0,0,1,1,1,1,1,1,2,2,2,2,2,2,2,2,3,3,3,3,4,4,4,4,5,5,6,6,6,6,6,

%T 6,6,6,6,6,7,7,8,8,8,8,8,8,9,9,9,9,9,9,10,10,11,11,11,11,12,12,12,12,

%U 12,12,13,13,13,13,14,14,14,14,14,14,14,14,15,15,16,16,16,16,17,17,17,17

%N Number of terms of A083207 that are not greater than n.

%C Partial sums of A179527: a(n) = SUM(A179527(k): 1<=k<=n);

%C A179529(n+1) = a(n+12) - a(n).

%H R. Zumkeller, <a href="/A179528/b179528.txt">Table of n, a(n) for n = 1..10000</a>

%H Peter Luschny, <a href="http://www.luschny.de/math/seq/ZumkellerNumbers.html">Zumkeller Numbers</a>

%e a(100)=#{6,12,20,24,28,30,40,42,48,54,56,60,66,70,78,80,84,88,90,96}=20;

%e a(1000000)=229026, by _T. D. Noe_.

%t 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]];

%t b[n_] := Boole[ZumkellerQ[n]];

%t Array[b, 100] // Accumulate (* _Jean-François Alcover_, Apr 30 2017, after _T. D. Noe_ *)

%K nonn

%O 1,12

%A _Reinhard Zumkeller_, Jul 19 2010

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Last modified June 15 10:58 EDT 2024. Contains 373407 sequences. (Running on oeis4.)