[seqfan] Factor Database

Hans Havermann pxp at rogers.com
Thu Sep 16 17:25:39 CEST 2010

I hadn't heard about this prior to Warut Roonguthai mentioning it this  
morning on MathFun in reference to the Triangular + Triangular =  
Factorial thread. For example, the factorizations of 4*z!+1 are:


Or, another example, the repunits:


When I generated the latter earlier, one of the factors for R186 was  
still shown as composite. I submitted the multiplication in the  
"report factors" at the top and upon refreshing the Repunits, the  
composite for R186 was gone! So we're talking real-time sharing here.

A final example. I had spent 11 months last year re-calculating  
Richard Guy's 776-term aliquot sequence for the number 46758. If  
you're willing to wait 20 seconds:


And you can show the graph with one click. I'm in heaven! ;)

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