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 A276046 #15 Jun 09 2024 18:06:25 %S A276046 1,2,10,16,78,97,125,138,192,242,290,373,408,467,583,892,899,1709, %T A276046 1944,2154,3618,5225,8974,9377,12504,20042,49106,63073,92152,147973 %N A276046 Numbers k such that (26*10^k - 23)/3 is prime. %C A276046 For k > 1, numbers k such that the digit 8 followed by k-2 occurrences of the digit 6 followed by the digits 59 is prime (see Example section). %C A276046 a(31) > 2*10^5. %H A276046 Makoto Kamada, <a href="https://stdkmd.net/nrr">Factorization of near-repdigit-related numbers</a>. %H A276046 Makoto Kamada, <a href="https://stdkmd.net/nrr/prime/prime_difficulty.txt">Search for 86w59</a>. %e A276046 2 is in this sequence because (26*10^2 - 23)/3 = 859 is prime. %e A276046 Initial terms and associated primes: %e A276046 a(1) = 1, 79; %e A276046 a(2) = 2, 859; %e A276046 a(3) = 10, 86666666659; %e A276046 a(4) = 16, 86666666666666659, etc. %t A276046 Select[Range[0, 100000], PrimeQ[(26*10^# - 23)/3] &] %o A276046 (PARI) is(n)=ispseudoprime((26*10^n - 23)/3) \\ _Charles R Greathouse IV_, Jun 13 2017 %Y A276046 Cf. A056654, A268448, A269303, A270339, A270613, A270831, A270890, A270929, A271269. %K A276046 nonn,more %O A276046 1,2 %A A276046 _Robert Price_, Aug 17 2016 %E A276046 a(30) from _Robert Price_, Dec 19 2019