This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
lst={}; k=100; Do[If[PrimeQ[k^n-(k-1)^n], Print[n]; AppendTo[lst, n]], {n, 10^5}]; lst (* Vladimir Joseph Stephan Orlovsky, Aug 26 2008 *)
forprime(p=2,1e5,if(ispseudoprime(100^p-99^p),print1(p", "))) \\ Charles R Greathouse IV, Jun 10 2011
k=7; Do[p=Prime[n]; f=(k^p-5^p)/(k-5); If[ PrimeQ[f], Print[p] ], {n,1,100}]
is(n)=isprime((7^n-5^n)/2) \\ Charles R Greathouse IV, Feb 17 2017
is(n)=ispseudoprime(21^n-20^n) \\ Charles R Greathouse IV, Jun 13 2017
k=6; Do[p=Prime[n]; f=(k^p+5^p)/(k+5); If[ PrimeQ[f], Print[p] ], {n,1,100}]
forprime(p=3,1e4,if(ispseudoprime((6^p+5^p)/11),print1(p", "))) \\ Charles R Greathouse IV, Jul 16 2011
k=11; Do[p=Prime[n]; f=(k^p-5^p)/(k-5); If[ PrimeQ[f], Print[p] ], {n,1,100}]
is(n)=isprime((11^n-5^n)/6) \\ Charles R Greathouse IV, Feb 17 2017
k=13; Do[p=Prime[n]; f=(k^p+5^p)/(k+5); If[ PrimeQ[f], Print[p] ], {n,1,100}]
is(n)=isprime((13^n+5^n)/18) \\ Charles R Greathouse IV, Feb 17 2017
k=12; Do[p=Prime[n]; f=(k^p+5^p)/(k+5); If[ PrimeQ[f], Print[p] ], {n,1,100}]
Select[Range[1100],PrimeQ[(12^#+5^#)/17]&] (* Harvey P. Dale, Jul 24 2012 *)
is(n)=isprime((12^n+5^n)/17) \\ Charles R Greathouse IV, Feb 17 2017
[n: n in [3..300] |IsPrime((9^n + 5^n) div 14)]; // Vincenzo Librandi, Nov 02 2018
k=9; Do[p=Prime[n]; f=(k^p+5^p)/(k+5); If[ PrimeQ[f], Print[p] ], {n,1,100}]
is(n)=isprime((9^n+5^n)/14) \\ Charles R Greathouse IV, Feb 17 2017
k=11; Do[p=Prime[n]; f=(k^p+5^p)/(k+5); If[ PrimeQ[f], Print[p] ], {n,1,100}]
is(n)=isprime((11^n+5^n)/16) \\ Charles R Greathouse IV, Feb 17 2017
Comments