Genocchi number
In mathematics, the Genocchi numbers Gn, named after Angelo Genocchi, are a sequence of integers that satisfy the relation 2 t 1 + e t = ∑ n = 0 ∞ G n t n n ! {\displaystyle {\frac {2t}{1+e^{t}}}=\sum _{n=0}^{\infty }G_{n}{\frac {t^{n}}{n!