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 A348554 #9 Dec 13 2021 17:07:25
%S A348554 2,2,3,2,4,2,5,2,3,4,6,2,7,2,4,8,2,3,6,9,2,4,5,10,2,11,2,3,4,6,8,12,2,
%T A348554 13,2,4,7,14,2,3,5,6,10,15,2,4,8,16,2,17,2,3,4,6,9,12,18,2,19,2,4,5,8,
%U A348554 10,20,2,3,6,7,14,21,2,4,11,22,2,23,2,3,4,6,8,12,16,24,2,5,10,25
%N A348554 Irregular triangle read by rows: row n gives the divisors d of 2*n with 1 < d < 2*n, for n >= 2.
%C A348554 This gives the rows 2*n of A137510, for n >= 2.
%C A348554 The length of row n is A069930(n) = tau(2*n) - 2 = A099777(n) - 2.
%C A348554 The sum of row n is A346880(n) = A062731(n) - (2*n + 1).
%F A348554 T(n, k) = A137510(2*n, k), for n >= 2 and k = 1, 2, ..., A069930(n).
%e A348554 The irregular triangle T(n, k) begins:
%e A348554 n, 2*n / k 1 2 3 4 5 6 7 ...
%e A348554 ----------------------------------
%e A348554 2, 4: 2
%e A348554 3, 6: 2 3
%e A348554 4, 8: 2 4
%e A348554 5, 10: 2 5
%e A348554 6 12: 2 3 4 6
%e A348554 7, 14: 2 7
%e A348554 8, 16: 2 4 8
%e A348554 9, 18: 2 3 6 9
%e A348554 10, 20: 2 4 5 10
%e A348554 11, 22: 2 11
%e A348554 12, 24: 2 3 4 6 8 12
%e A348554 13, 26: 2 13
%e A348554 14, 28: 2 4 7 14
%e A348554 15, 30: 2 3 5 6 10 15
%e A348554 16, 32: 2 4 8 1
%e A348554 17, 34: 2 17
%e A348554 18, 36: 2 3 4 6 9 12 18
%e A348554 19, 38: 2 19
%e A348554 20, 40: 2 4 5 8 10 20
%e A348554 ...
%t A348554 Flatten@Table[Select[Divisors[2n],1<#<2n&],{n,2,25}] (* _Giorgos Kalogeropoulos_, Oct 22 2021 *)
%o A348554 (PARI) row(n) = select(x->((x>1) && (x<2*n)), divisors(2*n)); \\ _Michel Marcus_, Oct 23 2021
%Y A348554 Cf. A069930, A099777, A137510, A346880.
%K A348554 nonn,tabf
%O A348554 2,1
%A A348554 _Wolfdieter Lang_, Oct 22 2021