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 A023351 #22 May 25 2024 13:58:39 %S A023351 294793,2586943,5360623,6351613,7965743,11141083,11378453,13458923, %T A023351 14884823,15585523,18691633,25387763,29964293,30766283,32388253, %U A023351 38647723,40653433,48716873,48786593,52628473,54270533,55507853,56575633,59103403 %N A023351 Primes that remain prime through 5 iterations of function f(x) = 8x + 9. %C A023351 Primes p such that 8*p+9, 64*p+81, 512*p+657, 4096*p+5265 and 32768*p+42129 are also primes. - _Vincenzo Librandi_, Aug 05 2010 %H A023351 John Cerkan, <a href="/A023351/b023351.txt">Table of n, a(n) for n = 1..10000</a> %F A023351 a(n) == 23 (mod 70). - _John Cerkan_, Nov 13 2016 %t A023351 prp5Q[n_]:=AllTrue[Rest[NestList[8#+9&,n,5]],PrimeQ]; Select[Prime[Range[3513000]],prp5Q] (* _Harvey P. Dale_, May 25 2024 *) %t A023351 prp5Q2[n_] := AllTrue[NestList[8 # + 9 &, n, 5], PrimeQ]; Select[Range[23, 59120000, 70], prp5Q2] (* Faster than the first Mathematica program above. *) (* _Harvey P. Dale_, May 25 2024 *) %o A023351 (Magma) [n: n in [1..19000000] | IsPrime(n) and IsPrime(8*n+9) and IsPrime(64*n+81) and IsPrime(512*n+657) and IsPrime(4096*n+5265) and IsPrime(32768*n+42129)] // _Vincenzo Librandi_, Aug 05 2010 %Y A023351 Subsequence of A023232, A023264, A023295, A023323, and of A153762. %K A023351 nonn %O A023351 1,1 %A A023351 _David W. Wilson_