%I A127980
%S A127980 1,5,14,37,90,213,490,1109,2474,5461,11946,25941,55978,120149,256682,
%T A127980 546133,1157802,2446677,5155498,10835285,22719146,47535445,99265194,
%U A127980 206918997,430615210,894784853,1856678570,3847574869,7963585194
%N A127980 Numbers of the form (n + 2/3)2^(n - 1) - 1/2 - ((-1)^(n - 1) )(1/6).
%D A127980 Bosma W. 2001. Signed bits and fast exponentiation. J. Th. des Nombres 
               de Bordeaux Vol.13, Fasc. 1
%H A127980 Bosma W. <a href="http://almira.math.u-bordeaux.fr/jtnb/2001-1/jtnb13-1.html#jourelec">
               Signed bits and fast exponentiation</a>.
%F A127980 a(n) = (n + 2/3)2^(n - 1) - 1/2 - ((-1)^(n - 1) )(1/6)
%t A127980 Table[(n + 2/3)2^(n - 1) - 1/2 - ((-1)^(n - 1) )(1/6), {n, 1, 50}], {n, 
               1, 100}] (*Artur Jasinski*)
%Y A127980 Cf. A073371, A127976, A127978, A127979, A073371.
%Y A127980 Sequence in context: A097507 A052951 A048745 this_sequence A054486 A072130 
               A045553
%Y A127980 Adjacent sequences: A127977 A127978 A127979 this_sequence A127981 A127982 
               A127983
%K A127980 nonn
%O A127980 1,2
%A A127980 Artur Jasinski (grafix(AT)csl.pl), Feb 09 2007