

A228868


Sum of all numbers n>=2 such that in their FermiDirac representation every A050376factor 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
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OFFSET

1,1


COMMENTS

Or, the same, diminished on 1 the sum of FermiDirac 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 A050376factor in their FermiDirac representation is A050376(n). Note also that the average of numbers n>=2 with A050376factors not exceeding A050376(n) is a(n)/(2^n1). 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



