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The terms of this sequence are integer values of consecutive denominators (with signs) from the fractional expansion (using only fractions with numerators to be positive 1's) of the BBP polynomial ( 4/(8*k+1) - 2/(8*k+4) - 1/(8*k+5) - 1/(8*k+6) ) for all k (starting from 0 to infinity); for k>=1 the Erdos-Straus conjecture is applied to the first fraction - so it is always replaced by exactly three fractions.
2

%I #3 Jul 07 2016 23:54:52

%S 1,1,1,1,-2,-5,-6,3,10,90,-5,-13,-14,5,30,510,-10,-21,-22,7,60,2100,

%T -14,-29,-30

%N The terms of this sequence are integer values of consecutive denominators (with signs) from the fractional expansion (using only fractions with numerators to be positive 1's) of the BBP polynomial ( 4/(8*k+1) - 2/(8*k+4) - 1/(8*k+5) - 1/(8*k+6) ) for all k (starting from 0 to infinity); for k>=1 the Erdos-Straus conjecture is applied to the first fraction - so it is always replaced by exactly three fractions.

%C This sequence is different from A154925, where the first fraction for k>=1 is expanded with Egyptians fractions, using R.Knott's converter calculator #1 (http://www.maths.surrey.ac.uk/hosted-sites/R.Knott/Fractions/egyptian.html#calc1)

%Y Cf. A073101, A075245, A075246, A075247, A154925

%K sign

%O 0,5

%A _Alexander R. Povolotsky_, Jan 18 2009, corrected Jan 20 2009