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 A288878 #10 Apr 14 2025 05:34:22
%S A288878 11,13,19,37,89,12329,209449,1106569,24344329,96342409,2504902409,
%T A288878 17961239296009,52580450364682240009,2295148179742698933452800009,
%U A288878 7825229077844441903818866688000009,145302140752338100885902776123355299840000009
%N A288878 Primes of the form k!3 + 3^2, where k!3 is the triple factorial number (A007661).
%H A288878 Robert Price, <a href="/A288878/b288878.txt">Table of n, a(n) for n = 1..24</a>
%H A288878 Henri and Renaud Lifchitz, <a href="http://www.primenumbers.net/prptop/searchform.php?form=n3+3^2&action=Search">PRP Records.Search for n!3+3^2</a>.
%H A288878 Joe McLean, <a href="http://web.archive.org/web/20091027034731/http://uk.geocities.com/nassarawa%40btinternet.com/probprim2.htm">Interesting Sources of Probable Primes</a>.
%H A288878 OpenPFGW Project, <a href="http://sourceforge.net/projects/openpfgw/">Primality Tester</a>.
%F A288878 a(n) = 9 + A007661(A247865(n)). - _Elmo R. Oliveira_, Apr 13 2025
%t A288878 MultiFactorial[n_, k_] := If[n<1, 1, n*MultiFactorial[n-k, k]];
%t A288878 Select[Table[MultiFactorial[i, 3] + 3^2, {i, 0, 100}], PrimeQ[#]&]
%Y A288878 Cf. A007661, A247865.
%K A288878 nonn
%O A288878 1,1
%A A288878 _Robert Price_, Jun 18 2017