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 A098429 #17 Feb 16 2025 08:32:54 %S A098429 0,0,1,1,1,1,2,2,2,2,2,2,3,3,3,3,3,3,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4, %T A098429 4,4,5,5,5,5,5,5,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,7,7, %U A098429 7,7,7,7,7,7,7,7,7,7,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,9,9,9,9,9,9,10,10 %N A098429 Number of cousin prime pairs (p, p+4) with p <= n. %C A098429 Convention: a prime pair is <= n iff its smallest member is <= n. %C A098429 Except for (3, 7), there is only 1 pair congruence class for cousin primes, i.e. (+1, -1) (mod 6). [_Daniel Forgues_, Aug 05 2009] %H A098429 Daniel Forgues, <a href="/A098429/b098429.txt">Table of n, a(n) for n=1..99996</a> %H A098429 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/CousinPrimes.html">Cousin Primes</a> %e A098429 First cousin prime pairs: (3,7),(7,11),(13,17),(19,23), ... %e A098429 therefore the sequence starts: 0 0 1 1 1 1 2 2 2 2 2 2 3 ... %t A098429 Accumulate[Table[If[PrimeQ[i]&&PrimeQ[i+4],1,0],{i,1,100}]] (* _Seiichi Kirikami_, May 28 2017 *) %Y A098429 Cf. A023200, A046132, A098428, A071538. %K A098429 nonn %O A098429 1,7 %A A098429 _Reinhard Zumkeller_, Sep 07 2004 %E A098429 Edited by _Daniel Forgues_, Aug 01 2009