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| OEIS [A071873][1] is an example of a selvage constant for which I would like to calculate millions/billions of digits. There *is* Mathematica code on the site but it does not scale very well. Using it, I run out of RAM after only a few hundred... |
| This was done in version 10.0.1 on a 4-year-old iMac running Yosemite: s = {27168, 27240, 27252, 27360}; Do[ Print[s[[i]], " ", Timing[PrimeQ[(10^s[[i]]*78880 - 1)/3]]], {i, 4}] 27168 {92.583833,False} 27240 ... |
| I'm looking for an instance of a prime for numbers of the form (10^n 78880-1)/3, where n is a positive integer. As a preliminary, it may be noted that n must be a multiple of 12. There are many other constraints based on division by small factors but... |
| **Interrupt Evaluation** is missing from the menu of Mathematica 10! It's also one of my most-often used procedures in version 9 whereby I save partial results in long-running programs. How do I now interrupt an evaluation? How do I continue it? |
| For large lists (where you don't have enough memory to store the entire array), I used to do this with the Combinatorica NthPermutation, now apparently UnrankPermutation. And it worked fine with lists composed of all different... |
| I am on a quest to determine the 13th term in [url=http://oeis.org/A229024]Sloane's (OEIS) A229024[/url], a sequence that I recently authored. This sequence is all about calculating Total[IntegerDigits[n!] for a reasonably large subset... |