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.
%I A225945 #13 May 25 2023 11:01:29 %S A225945 1,6,60,136,124796,3919272,18363918,153037808,965108649,3140421892, %T A225945 5961162423,20437804784 %N A225945 Numbers k such that prime(k) divides k^k + 1. %C A225945 a(12) > 2*10^10. - _Giovanni Resta_, May 23 2013 %t A225945 Select[Range[10^6], (p = Prime[#]; PowerMod[#, #, p] == p - 1) &] (* _Giovanni Resta_, May 23 2013 *) %o A225945 (Python) %o A225945 from sympy import nextprime, prime %o A225945 from itertools import count, islice %o A225945 def agen(startn=1): # generator of terms %o A225945 pn = prime(startn) %o A225945 for n in count(startn): %o A225945 if pow(n, n, pn) == pn - 1: %o A225945 yield n %o A225945 pn = nextprime(pn) %o A225945 print(list(islice(agen(), 5))) # _Michael S. Branicky_, May 25 2023 %Y A225945 Cf. A000040, A000312, A014566, A225944. %K A225945 nonn,more %O A225945 1,2 %A A225945 _Alex Ratushnyak_, May 21 2013 %E A225945 a(6)-a(11) from _Giovanni Resta_, May 23 2013 %E A225945 a(12) from _Michael S. Branicky_, May 25 2023