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 A242123 #18 Dec 12 2024 09:29:50
%S A242123 2,3,5,7,11,13,17,19,23,4,6,12,16,18,22,3,9,11,17,21,23,4,8,14,22,1,3,
%T A242123 7,9,13,2,6,12,14,24,1,7,13,17,23,4,6,16,18,22,24,11,23,2,4,8,14,16,1,
%U A242123 7,13,19,21,2,6,8,18,7,11,13,17,6,12,22,24,3,9,17
%N A242123 a(n) = n-th prime modulo 25.
%H A242123 Vincenzo Librandi, <a href="/A242123/b242123.txt">Table of n, a(n) for n = 1..1000</a>
%F A242123 Sum_k={1..n} a(k) ~ (25/2)*n. - _Amiram Eldar_, Dec 12 2024
%t A242123 Mod[Prime[Range[100]], 25]
%o A242123 (Magma) [p mod(25): p in PrimesUpTo(500)];
%o A242123 (PARI) a(n) = prime(n) % 25; \\ _Michel Marcus_, May 05 2014
%o A242123 (Sage) [mod(p, 25) for p in primes(500)] # _Bruno Berselli_, May 05 2014
%Y A242123 Cf. similar sequences listed in A242119.
%K A242123 nonn,easy
%O A242123 1,1
%A A242123 _Vincenzo Librandi_, May 05 2014