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 A023296 #30 Aug 28 2024 14:46:23 %S A023296 19,103,113,151,239,283,313,599,929,1481,2411,2549,2593,2741,2819, %T A023296 2969,3931,4091,4463,4523,5279,5923,6781,7759,8209,8363,9749,10133, %U A023296 10531,12919,14071,15053,15361,16229,16453,16493,16573,16703,17041,17783,18253 %N A023296 Primes that remain prime through 3 iterations of function f(x) = 9x + 2. %C A023296 Primes p such that 9*p+2, 81*p+20 and 729*p+182 are also primes. - _Vincenzo Librandi_, Aug 04 2010 %H A023296 John Cerkan, <a href="/A023296/b023296.txt">Table of n, a(n) for n = 1..10000</a> %p A023296 A023296:=n->`if`(isprime(n) and isprime(9*n+2) and isprime(81*n+20) and isprime(729*n+182), n, NULL): seq(A023296(n), n=1..5*10^4); # _Wesley Ivan Hurt_, Feb 22 2017 %t A023296 Select[Prime@ Range@ 2100, Times @@ Boole@ PrimeQ@ NestList[9 # + 2 &, #, 3] > 0 &] (* _Michael De Vlieger_, Feb 22 2017 *) %t A023296 Select[Prime[Range[2100]],AllTrue[Rest[NestList[9#+2&,#,3]],PrimeQ]&] (* _Harvey P. Dale_, May 14 2024 *) %o A023296 (Magma) [n: n in [1..450000] | IsPrime(n) and IsPrime(9*n+2) and IsPrime(81*n+20) and IsPrime(729*n+182)]; // _Vincenzo Librandi_, Aug 04 2010 %Y A023296 Subsequence of A023233 and A023265. %K A023296 nonn %O A023296 1,1 %A A023296 _David W. Wilson_