@FelipeSoares - I believe that ! will compute the gamma function, effectively working as factorial for non-integers. ×/⍳⍵ will only work for integers (⍵=⌊⍵).

And you can apply inverse to !: ⋄ !⍣¯1⊢12

@LdBeth 3.52239791

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@BoazC To run APL code, write code blocks starting with ⎕← or ⋄ or write a multi-line code block and prepend ⎕← or ⋄ to lines you wish to run. All matching groups / lines will be joined by ⋄ and run via TryAPL, and the output will be posted here. To format a codeblock, write `code`, or for a multi-line code block, use Shift+Enter to type multiple lines and press Ctrl-K, press the 'fixed font' button, or prepend four spaces to each line.

@BoazC Very nice. Check out apl.wiki/Learning_resources too, but don't be a stranger; let people here know if you need anything.