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 A237189 #19 May 03 2021 20:15:22 %S A237189 330,1530,3060,4260,4950,6840,10830,15390,18120,23010,25410,26040, %T A237189 31770,33300,40110,41490,45060,49830,53880,59340,65850,70140,73770, %U A237189 78540,88740,95460,96930,109470,111720,112620,117720,131310,133200,134730,135300,150150,165900 %N A237189 Numbers k such that k+1, 2k+1, 3k+1, 4k+1 are all prime. %C A237189 A subsequence of A064238. %C A237189 All terms are divisible by 30, and b(n)=a(n)/30 begins: 11, 51, 102, 142, 165, 228, 361, 513, 604, 767, 847, 868, 1059, 1110, 1337, 1383, 1502, 1661, 1796, 1978, 2195, ... %H A237189 Jon E. Schoenfield, <a href="/A237189/b237189.txt">Table of n, a(n) for n = 1..10000</a> (first 1000 terms from Giovanni Resta) %F A237189 a(n) = 2*(A105653(n) + 1) = 2*A124409(n). - _Hugo Pfoertner_, May 03 2021 %o A237189 (Python) %o A237189 import sympy %o A237189 from sympy import isprime %o A237189 for n in range(0,100000,2): %o A237189 if isprime(n+1) and isprime(2*n+1) and isprime(3*n+1) and isprime(4*n+1): %o A237189 print(str(n), end=',') %Y A237189 Cf. A088250, A064238, A105653, A124409. %K A237189 nonn %O A237189 1,1 %A A237189 _Alex Ratushnyak_, Feb 04 2014