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A228868 Sum of all numbers n>=2 such that in their Fermi-Dirac representation every A050376-factor does not exceed A050376(n). 1

%I

%S 2,11,59,359,2879,28799,345599,4838399,82252799,1480550399,

%T 29611007999,710664191999,18477268991999,554318069759999,

%U 17738178232319999,674050772828159999,28310132458782719999,1245645828186439679999,59790999752949104639999

%N Sum of all numbers n>=2 such that in their Fermi-Dirac representation every A050376-factor does not exceed A050376(n).

%C Or, the same, diminished on 1 the sum of Fermi-Dirac divisors of the number prod{i=1,...,n} A050376(i). Note that the sequence of the first differences 2, 9, 48, 300,... lists sums of all numbers such that the maximal A050376-factor in their Fermi-Dirac representation is A050376(n). Note also that the average of numbers n>=2 with A050376-factors not exceeding A050376(n) is a(n)/(2^n-1). Thus the sequence of such averages begins 2, 11/3, 59/7, 359/15,...

%C Prime terms are 2, 11, 59, 359, 2879, 345599, 4838399,...

%H Peter J. C. Moses, <a href="/A228868/b228868.txt">Table of n, a(n) for n = 1..100</a>

%F a(n) = prod{i=1,...,n}(A050376(i)+1) - 1.

%e a(3) = 2 + 3 + 2*3 = 11.

%Y Cf. A050376.

%K nonn

%O 1,1

%A _Vladimir Shevelev_ and _Peter J. C. Moses_, Sep 06 2013

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Last modified September 27 04:10 EDT 2021. Contains 347673 sequences. (Running on oeis4.)