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 A309333 #16 May 14 2023 04:14:21 %S A309333 1,1,4,0,1,4,1,0,8,4,1,5,2,0,4,7,1,3,2,2,6,1,1,5,2,6,5,3,1,1,0,1,4,6, %T A309333 1,4,1,4,9,5,7,0,0,2,2,5,1,3,0,8,4,1,5,2,18,0,9,3,1,1,9,2,4,5,3,2,6,5, %U A309333 4,9,3,4,11,1,1,3,4,20,0,8,2,4,3,3,15,6 %N A309333 The number of primes between two consecutive lucky primes, bounds excluded. %H A309333 Amiram Eldar, <a href="/A309333/b309333.txt">Table of n, a(n) for n = 1..10000</a> %e A309333 a(1): Between the first two lucky primes (3, 7) there is one prime (5). %e A309333 a(3): Between 13 and 31 there are 4 primes (17, 19, 23, 29). %o A309333 (SageMath) %o A309333 def count_primes_between(a, b): %o A309333 return len(prime_range(a+1, b)) %o A309333 [count_primes_between(A031157[i], A031157[i+1]) for i in range (len(A031157[0:20])-1)] %Y A309333 Cf. A000959, A031157, A309334, A176559. %K A309333 nonn %O A309333 1,3 %A A309333 _Hauke Löffler_, Jul 24 2019