http://gosper.org/¼!.png Just the n=0 term: Out[67]= (1/4)! - √(5GoldenRatio) π^(3/4)/(√√√2 (√√5-1)E^(5π/6)) In[68]:= N[%, 9] Out[68]= -4.67513339*10^-28 —rwg MMachinable series: (1/4)! == π^(3/4) √(5 GoldenRatio) Sum[(-1)^n/E^(30π(n+1/6)^2),{n,-∞,∞}]/(√√√2(√√5 - 1))