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 A127430 #20 Feb 09 2025 17:24:07 %S A127430 2,3,7,11,13,17,31,41,59,71,73,97,113,139,157,193,239,269,277,311,337, %T A127430 349,421,449,487,577,587,619,643,701,811,823,827,941,977,1021,1051, %U A127430 1093,1217,1249,1259,1361,1373,1471,1571,1721,1723,1747,1777,1789,1861,1907 %N A127430 Primes p such that 6p-5 and 6p+5 are also primes. %C A127430 Subsequence of primes p such that 6p-5 and 6p+5 are consecutive primes: 31, 41, 71, 97, 139, 193, 337, 349, 421, 487, 587, 619, 643, 701, 811, 827, 1021, 1051, 1093, 1217, 1249, 1259, 1471, 1571, 1721, 1747, .... - _Zak Seidov_, Mar 27 2017 %e A127430 Example: 11, 6*11+5=71, 6*11-5=61 are all primes. %p A127430 A127430:=n->`if`(isprime(n) and isprime(6*n-5) and isprime(6*n+5),n,NULL): seq(A127430(n), n=1..2000); # _Wesley Ivan Hurt_, Oct 23 2014 %t A127430 Select[Range[5000], PrimeQ[ # ] && PrimeQ[6# + 5] && PrimeQ[6# - 5] &] %o A127430 (Magma) [ p: p in PrimesUpTo(9000) | IsPrime(6*p-5) and IsPrime(6*p+5)]; // _Vincenzo Librandi_, Jan 29 2011 %o A127430 (PARI) is(n)=isprime(n) && isprime(6*n-5) && isprime(6*n+5) \\ _Charles R Greathouse IV_, Mar 28 2017 %K A127430 nonn %O A127430 1,1 %A A127430 _Zerinvary Lajos_, Mar 31 2007