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 A265683 #38 Sep 08 2022 08:46:15 %S A265683 1,27,52,56,60,252,270,367,390,2154,3247,13444,35724,46917,79236,87324 %N A265683 Numbers n such that 16^n * (16^n - 1) - 1 is prime. %C A265683 Each of the corresponding numbers of the form 16^n * (16^n - 1) - 1 is almost a repdigit in base 16 (i.e., a repdigit with only one change). %C A265683 n is in the sequence iff 4*n is in A098845. - _Robert Israel_, Dec 14 2015 %H A265683 Brady Haran and Simon Pampena, <a href="https://www.youtube.com/watch?v=HPfAnX5blO0">Glitch Primes and Cyclops Numbers</a>, Numberphile video (2015) %t A265683 Select[Range[1000], PrimeQ[16^# (16^# - 1) - 1] &] (* _Shivam Patel_, Dec 13 2015 *) %o A265683 (PARI) is(n)=ispseudoprime(16^n * (16^n - 1) - 1) \\ _Anders Hellström_, Dec 13 2015 %o A265683 (Magma) [n: n in [1..200] | IsPrime(256^n-16^n-1)]; // _Vincenzo Librandi_, Dec 14 2015 %Y A265683 Cf. A098845, similar sequences listed in A265481. %K A265683 nonn,more %O A265683 1,2 %A A265683 _Shivam N. Patel_, Dec 13 2015 %E A265683 a(12)-a(16) computed from A098845 by _Ray Chandler_, Sep 25 2019