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 A258932 #25 Apr 28 2025 07:12:55 %S A258932 1,3,4,5,7,9,10,11,27,35,85,169,209,221,321,347,603,610,1229,1391, %T A258932 2171,2303,2679,3977,4545,5721,7090,35877 %N A258932 Numbers k such that 10^k + 103 is prime. %C A258932 a(29) > 60000. - _Michael S. Branicky_, Apr 27 2025 %e A258932 For n = 3, a(3) = 10^3 + 103 = 1103, which is prime. %t A258932 Select[Range[5000], PrimeQ[10^# + 103] &] %o A258932 (Magma) [n: n in [1..600] | IsPrime(10^n+103)]; %o A258932 (PARI) is(n)=ispseudoprime(10^n+103) \\ _Charles R Greathouse IV_, Jun 13 2017 %Y A258932 Sequences of the type 10^n+k: A049054 (k=3), A088274 (k=7), A088275 (k=9), A095688 (k=13), A108052 (k=19), A108050 (k=21), A108312 (k=27), A107083 (k=31), A107084 (k=33), A135109 (k=37), A135108 (k=39), A108049 (k=43), A108054 (k=49), A135118 (k=51), A135119 (k=57), A135116 (k=61), A135115 (k=63), A135113 (k=67), A135114 (k=69), A135132 (k=73), A135131 (k=79), A137848 (k=81), A135117 (k=87), A110918 (k=91), A135112 (k=93), A135107 (k=97), A110980 (k=99), this sequence (k=103), A258933 (k=109), A165508 (k=111), A248349 (k=123456789), A248351 (k=987654321). %K A258932 nonn,more %O A258932 1,2 %A A258932 _Vincenzo Librandi_, Jun 15 2015 %E A258932 a(26)-a(28) from _Jens Kruse Andersen_, Jun 23 2015