Source: wikibot/1-minus-1-plus-2-minus-6-plus-24-minus-120-plus-⋯

= 1 − 1 + 2 − 6 + 24 − 120 + ⋯
{wiki=1_−_1_+_2_−_6_+_24_−_120_+_⋯}

Back to article page