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 A274986 #48 May 11 2024 20:22:28 %S A274986 1,2,6,146,326,380,1116,1866,4808,5528,5730,21836,24804,38724 %N A274986 Numbers k such that (10^k + 23)/3 is prime. %C A274986 Also numbers k for which A093137(k) + 7 or A002277(k) + 8 is prime. %t A274986 Select[Range[1000], PrimeQ[(10^# + 23) / 3] &] %o A274986 (Magma) [n: n in [0..400] | IsPrime((10^n+23) div 3)]; %o A274986 (PARI) is(n)=ispseudoprime((10^n+23)/3) \\ _Charles R Greathouse IV_, Jun 13 2017 %Y A274986 Cf. numbers k such that (10^k+m)/3 is prime: A099411 (m=11), this sequence (m=23). %Y A274986 Cf. A002277, A093137. %K A274986 nonn,less,more %O A274986 1,2 %A A274986 _Vincenzo Librandi_, Sep 25 2016 %E A274986 a(9)-a(11) from _Michael S. Branicky_, Aug 16 2021 %E A274986 a(12)-a(13) from _Michael S. Branicky_, May 14 2023 %E A274986 a(14) from Kamada data by _Tyler Busby_, May 05 2024