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 A364321 #13 Oct 09 2023 18:37:55 %S A364321 97,191,293,347,401,409,479,727,1823,1931,2063,2089,2897,2903,2999, %T A364321 3061,3083,3119,3571,3617,3673,3727,3967,4339,4373,4583,4639,4703, %U A364321 4813,5297,5347,5437,5639,5821,6047,6053,6311,6421,6491,6529,6761,6883,7283,7417,7451,7949,8059,8123,8237 %N A364321 Prime numbers that are the exact average of nine consecutive odd semiprimes. %e A364321 97 is a term because (77 + 85 + 87 + 91 + 93 + 95 + 111 + 115 + 119)/9 = 97 is prime. %e A364321 401 is a term because (381 + 391 + 393 + 395 + 403 + 407 + 411 + 413 + 415)/9 = 401 is prime. %t A364321 Select[Mean /@ Partition[Select[Range[1, 9000, 2], PrimeOmega[#] == 2 &], 9, 1], PrimeQ] (* _Amiram Eldar_, Sep 25 2023 *) %Y A364321 Cf. A000040, A046315. %Y A364321 Cf. A363074, A363187, A363188, A364147, A364148, A364149, A364320, A364689. %K A364321 nonn %O A364321 1,1 %A A364321 _Elmo R. Oliveira_, Sep 25 2023