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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
 2, 11, 59, 359, 2879, 28799, 345599, 4838399, 82252799, 1480550399, 29611007999, 710664191999, 18477268991999, 554318069759999, 17738178232319999, 674050772828159999, 28310132458782719999, 1245645828186439679999, 59790999752949104639999 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS 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,... Prime terms are 2, 11, 59, 359, 2879, 345599, 4838399,... LINKS Peter J. C. Moses, Table of n, a(n) for n = 1..100 FORMULA a(n) = prod{i=1,...,n}(A050376(i)+1) - 1. EXAMPLE a(3) = 2 + 3 + 2*3 = 11. CROSSREFS Cf. A050376. Sequence in context: A054564 A280674 A139172 * A290116 A251180 A286194 Adjacent sequences:  A228865 A228866 A228867 * A228869 A228870 A228871 KEYWORD nonn AUTHOR Vladimir Shevelev and Peter J. C. Moses, Sep 06 2013 STATUS approved

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Last modified July 24 02:31 EDT 2021. Contains 346270 sequences. (Running on oeis4.)