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 A351846 #54 Jun 04 2023 19:50:14
%S A351846 0,1,1,1,1,1,2,2,2,2,2,2,2,2,2,3,3,3,3,3,3,3,3,3,3,3,3,3,4,4,4,4,4,4,
%T A351846 4,4,4,4,4,4,4,4,4,4,4,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,6,6,
%U A351846 6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6
%N A351846 Irregular triangle read by rows: T(n,k), n >= 0, k >= 0, in which n appears 4*n + 1 times in row n.
%C A351846 a(n) is the number of hexagonal numbers A000384 less than or equal to n, not counting 0 as hexagonal.
%C A351846 This sequence is related to hexagonal numbers as A003056 is related to triangular numbers (or generalized hexagonal numbers) A000217.
%F A351846 a(n) = floor((sqrt(8*n + 1) + 1)/4). - _Ridouane Oudra_, Apr 09 2023
%e A351846 Triangle begins:
%e A351846 0;
%e A351846 1, 1, 1, 1, 1;
%e A351846 2, 2, 2, 2, 2, 2, 2, 2, 2;
%e A351846 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3;
%e A351846 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4;
%e A351846 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5;
%e A351846 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6;
%e A351846 ...
%t A351846 Table[PadRight[{},4n+1,n],{n,0,7}]//Flatten (* _Harvey P. Dale_, Jun 04 2023 *)
%Y A351846 Row sums give A007742.
%Y A351846 Row n has length A016813(n).
%Y A351846 Column 0 gives A001477, the same as the right border.
%Y A351846 Nonzero terms give the row lengths of the triangles A347263, A347529, A351819, A351824, A352269, A352499.
%Y A351846 Cf. A000217, A000384, A003056.
%K A351846 nonn,tabf,easy
%O A351846 0,7
%A A351846 _Omar E. Pol_, Feb 21 2022