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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.

A339399 Pairwise listing of the partitions of k into two parts (s,t), with 0 < s <= t ordered by increasing values of s and where k = 2,3,... .

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%I A339399 #37 Jan 09 2022 00:16:27
%S A339399 1,1,1,2,1,3,2,2,1,4,2,3,1,5,2,4,3,3,1,6,2,5,3,4,1,7,2,6,3,5,4,4,1,8,
%T A339399 2,7,3,6,4,5,1,9,2,8,3,7,4,6,5,5,1,10,2,9,3,8,4,7,5,6,1,11,2,10,3,9,4,
%U A339399 8,5,7,6,6,1,12,2,11,3,10,4,9,5,8,6,7,1,13,2,12,3,11
%N A339399 Pairwise listing of the partitions of k into two parts (s,t), with 0 < s <= t ordered by increasing values of s and where k = 2,3,... .
%C A339399 a(n-1) and a(n) are the lesser and greater of a twin prime pair if and only if a(n) = a(n-1) + 2 where a(n-1) and a(n) are prime.
%H A339399 <a href="/index/Par#part">Index entries for sequences related to partitions</a>
%F A339399 a(n) = (1+(-1)^n)*(1+floor(sqrt(2*n-1-(-1)^n)))/2-((2*n+1-(-1)^n)/2-2 *Sum_{k=1..floor(sqrt(2*n-2-(-1)^n)-1)} floor((k+1)/2))*(-1)^n/2.
%F A339399 a(n) = A339443(A103889(n)). - _Wesley Ivan Hurt_, May 09 2021
%e A339399                                                                      [1,9]
%e A339399                                                      [1,7]   [1,8]   [2,8]
%e A339399                                      [1,5]   [1,6]   [2,6]   [2,7]   [3,7]
%e A339399                      [1,3]   [1,4]   [2,4]   [2,5]   [3,5]   [3,6]   [4,6]
%e A339399      [1,1]   [1,2]   [2,2]   [2,3]   [3,3]   [3,4]   [4,4]   [4,5]   [5,5]
%e A339399    k   2       3       4       5       6       7       8       9      10
%e A339399   --------------------------------------------------------------------------
%e A339399    k   Nondecreasing partitions of k
%e A339399   --------------------------------------------------------------------------
%e A339399    2   1,1
%e A339399    3   1,2
%e A339399    4   1,3,2,2
%e A339399    5   1,4,2,3
%e A339399    6   1,5,2,4,3,3
%e A339399    7   1,6,2,5,3,4
%e A339399    8   1,7,2,6,3,5,4,4
%e A339399    9   1,8,2,7,3,6,4,5
%e A339399   10   1,9,2,8,3,7,4,6,5,5
%e A339399   ...
%t A339399 t[n_] := Flatten[Reverse /@ IntegerPartitions[n, {2}]]; Array[t, 14, 2] // Flatten (* _Amiram Eldar_, Dec 03 2020 *)
%t A339399 Table[(1 + (-1)^n) (1 + Floor[Sqrt[2 n - 1 - (-1)^n]])/2 - ((2 n + 1 - (-1)^n)/2 - 2 Sum[Floor[(k + 1)/2], {k, -1 + Floor[Sqrt[2 n - 2 - (-1)^n]]}]) (-1)^n/2, {n, 100}] (* _Wesley Ivan Hurt_, Dec 04 2020 *)
%o A339399 (PARI) row(n) = vector(n\2, i, [i, n-i]);
%o A339399 tabf(nn) = for (n=2, nn, print(row(n))); \\ _Michel Marcus_, Dec 03 2020
%Y A339399 Cf. A103889, A339443.
%Y A339399 Bisections: A122197 (odd), A199474 (even).
%K A339399 nonn,tabf
%O A339399 1,4
%A A339399 _Wesley Ivan Hurt_, Dec 02 2020