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 A057181 #39 Oct 24 2024 14:17:27 %S A057181 3,7,29,1091,2423,54449,67489,551927,1841911,1848811 %N A057181 Numbers n such that (15^n + 1)/16 is a prime. %C A057181 a(6), a(7) and a(8) correspond to probable primes. %H A057181 Paul Bourdelais, <a href="https://listserv.nodak.edu/cgi-bin/wa.exe?A2=NMBRTHRY;417ab0d6.0906">A Generalized Repunit Conjecture</a> %H A057181 J. Brillhart et al., <a href="http://dx.doi.org/10.1090/conm/022">Factorizations of b^n +- 1</a>, Contemporary Mathematics, Vol. 22, Amer. Math. Soc., Providence, RI, 3rd edition, 2002. %H A057181 H. Dubner and T. Granlund, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL3/DUBNER/dubner.html">Primes of the Form (b^n+1)/(b+1)</a>, J. Integer Sequences, 3 (2000), #P00.2.7. %H A057181 H. Lifchitz, <a href="http://www.primenumbers.net/Henri/us/MersFermus.htm">Mersenne and Fermat primes field</a> %t A057181 Select[Range[3000], PrimeQ[(15^# + 1) / 16] &] (* _Vincenzo Librandi_, Oct 29 2017 *) %o A057181 (Prime95) PRP=1,15,551927,1,0,0,"16" %o A057181 (PARI) isok(n) = (denominator(p=(15^n+1)/16)==1) && isprime(p); \\ _Michel Marcus_, Oct 29 2017 %K A057181 nonn,more %O A057181 1,1 %A A057181 _N. J. A. Sloane_, Sep 15 2000 %E A057181 a(6) from _Paul Bourdelais_, Mar 15 2010 %E A057181 a(7) from _Paul Bourdelais_, Mar 16 2010 %E A057181 a(8) from _Paul Bourdelais_, Jul 03 2013 %E A057181 a(9)-a(10) from _Paul Bourdelais_, Jul 08 2024