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 A028874 #66 Mar 02 2025 08:00:18
%S A028874 13,61,97,193,397,673,1021,1153,1597,1933,2113,3361,4093,4621,6397,
%T A028874 7393,7741,8461,9601,12097,12541,13921,15373,16381,18493,19597,20161,
%U A028874 21313,26893,29581,36097,37633,40801,42433,43261,47521,48397
%N A028874 Primes of form k^2 - 3.
%C A028874 Also primes equal to the product of two consecutive odd numbers (A000466) minus 2. - _Giovanni Teofilatto_, Feb 11 2010
%C A028874 All terms are of the form 6m + 1. - _Zak Seidov_, May 01 2014
%H A028874 Nathaniel Johnston, <a href="/A028874/b028874.txt">Table of n, a(n) for n = 1..10000</a>
%H A028874 Patrick De Geest, <a href="http://www.worldofnumbers.com/consemor.htm">Palindromic Quasipronics of the form n(n+x)</a>.
%H A028874 R. J. Mathar, <a href="https://vixra.org/abs/2210.0029">Solutions to the exponential Diophantine 1 + p_1^x + p_2^y + p_3^z = w^2 for distinct primes p_1, p_2, p_3</a>, 2022.
%H A028874 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Near-SquarePrime.html">Near-Square Prime</a>.
%F A028874 A028872 INTERSECT A000040. - _Klaus Purath_, Dec 07 2020
%F A028874 a(n) = A028873(n)^2 - 3. - _Amiram Eldar_, Mar 01 2025
%e A028874 61 is prime and equal to 8^2 - 3, so it is in the sequence.
%e A028874 67 is prime but it's 8^2 + 3 = 9^2 - 14, so it is not in the sequence.
%e A028874 9^2 - 3 = 78 but it's composite, so it's not in the sequence either.
%t A028874 Select[Range[2, 250]^2 - 3, PrimeQ] (* _Harvey P. Dale_, Aug 07 2013 *)
%t A028874 Select[Table[n^2 - 3, {n, 2, 300}], PrimeQ] (* _Vincenzo Librandi_, Nov 08 2014 *)
%o A028874 (Magma) [a: n in [2..300] | IsPrime(a) where a is n^2-3 ]; // _Vincenzo Librandi_, Nov 08 2014
%o A028874 (PARI) select(isprime, vector(100,n,n^2-3)) \\ _Charles R Greathouse IV_, Nov 19 2014
%Y A028874 Cf. A002476 (Primes of form 6m + 1), A028871, A028872, A028873.
%Y A028874 Primes terms in A082109. Subsequence of A068228. - _Klaus Purath_, Jan 09 2023
%K A028874 nonn
%O A028874 1,1
%A A028874 _Patrick De Geest_