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 A265651 #19 May 22 2025 10:21:44 %S A265651 14592,84348,151938,208962,241392,254490,397182,420192,494442,527700, %T A265651 549978,581982,637200,641550,712602,729330,791628,850302,975552, %U A265651 995052,1086558,1107852,1157670,1245450,1260798,1286148,1494510,1555290,1608912 %N A265651 Numbers n such that n-29, n-1, n+1 and n+29 are consecutive primes. %C A265651 This sequence is a subsequence of A014574 (average of twin prime pairs) and A256753. %C A265651 The terms ending in 0 are divisible by 30 (cf. A249674). %C A265651 The terms ending in 2 and 8 are congruent to 12 mod 30 and 18 mod 30 respectively. %C A265651 The numbers n-29 and n+1 belong to A252090 (p and p+28 are primes) and A124595 (p where p+28 is the next prime). %C A265651 The numbers n-29 and n-1 belong to A049481 (p and p+30 are primes). %H A265651 Karl V. Keller, Jr., <a href="/A265651/b265651.txt">Table of n, a(n) for n = 1..10000</a> %H A265651 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/TwinPrimes.html">Twin Primes</a> %e A265651 14592 is the average of the four consecutive primes 14563, 14591, 14593, 14621. %e A265651 84348 is the average of the four consecutive primes 84319, 84347, 84349, 84377. %t A265651 Select[Prime@Range@100000, NextPrime[#, {1, 2, 3}] == {28, 30, 58} + # &] + 29 (* _Vincenzo Librandi_, Dec 12 2015 *) %t A265651 Mean/@Select[Partition[Prime[Range[125000]],4,1],Differences[#]=={28,2,28}&] (* _Harvey P. Dale_, May 02 2016 *) %o A265651 (Python) %o A265651 from sympy import isprime,prevprime,nextprime %o A265651 for i in range(0,1000001,6): %o A265651 if isprime(i-1) and isprime(i+1) and prevprime(i-1) == i-29 and nextprime(i+1) == i+29 : print (i,end=', ') %Y A265651 Cf. A014574, A077800 (twin primes), A249674, A256753. %K A265651 nonn %O A265651 1,1 %A A265651 _Karl V. Keller, Jr._, Dec 11 2015