A180878 - OEIS

%I #2 Mar 30 2012 18:53:10

%S 1,0,-1,-1,-9,-5,-21,-21,-197,-117,-427,-427,-2501,-1797,-2909,-2909,

%T -72877,-65453

%N Numerator in fraction A180878/A060818.

%C The generating function 1/sqrt((1/x-1)*(1/x+1)) is symmetrical around the origin and has singularities at -1 and +1.

%F Lambert series: Sum_{n >= 1} A180878(n)/A060818(n)*(x^n/(1-x^n)-x^(n+1)/(1-x^(n+1)))=1/sqrt((1/x-1)*(1/x+1)).

%Y Cf. Analogous to fraction A180403/A046161.

%K sign

%O 1,5

%A _Mats Granvik_, Sep 23 2010