Lambert-series-type-representation-for-1-factorial-i-i-i-i-1-2-n-1-1-n-e-n-2-1-

Question Number 163548 by HongKing last updated on 07/Jan/22

Lambert series type representation

for \sqrt{- 1} factorial

(i^{i})! (- i^{i})! = 1 - 2 \underset{n = 1}{\sum^{\infty}} \frac{{(- 1)}^{n}}{e^{π} n^{2} - 1}