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 A308044 #9 May 11 2019 02:22:11
%S A308044 0,0,2,4,2,8,10,8,14,16,14,20,18,16,26,28,26,24,34,32,38,40,38,44,42,
%T A308044 40,50,48,46,56,58,56,54,64,62,68,70,68,66,76,74,80,78,76,86,84,82,80,
%U A308044 94,92,98,100,98,104,106,104,110,108,106,104,102,100,98,124
%N A308044 a(n) = 2*prevprime(2*n-1) - 2*n, where prevprime(n) is the largest prime < n.
%C A308044 a(n) is the difference between the parts in the single partition of 2*n into two parts such that the larger part is the biggest prime < 2*n - 1.
%C A308044 For n > 1, the sequence of terms agrees with A303603 up to a(48), but a(49) = 80, whereas A303603(49) = 60. (This is because the smallest prime less than 2*49 - 1 = 97 is 89, which is paired with 9. This is the first instance in which the largest prime < 2*n - 1 is not paired with a prime. Regardless of whether the smallest part is prime or composite, we take the difference. So a(49) = 89 - 9 = 80.)
%H A308044 <a href="/index/Par#part">Index entries for sequences related to partitions</a>
%F A308044 a(n) = 2*A151799(2*n - 1) - 2*n.
%t A308044 Table[2 NextPrime[2 n - 1, -1] - 2 n, {n, 2, 100}]
%o A308044 (PARI) a(n) = 2*precprime(2*n-2) - 2*n; \\ _Michel Marcus_, May 10 2019
%Y A308044 Cf. A151799, A303603.
%K A308044 nonn,easy
%O A308044 2,3
%A A308044 _Wesley Ivan Hurt_, May 10 2019