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 A286157 #18 Nov 09 2024 14:48:00
%S A286157 1,3,2,6,1,2,10,4,5,2,15,3,1,5,2,21,7,4,9,5,2,28,6,8,1,9,5,2,36,11,3,
%T A286157 4,14,9,5,2,45,10,7,8,1,14,9,5,2,55,16,12,13,4,20,14,9,5,2,66,15,6,3,
%U A286157 8,1,20,14,9,5,2,78,22,11,7,13,4,27,20,14,9,5,2,91,21,17,12,19,8,1,27,20,14,9,5,2,105,29,10,18,3,13,4,35,27,20,14,9,5,2
%N A286157 Transpose of square array A286156.
%C A286157 See A286156.
%H A286157 Antti Karttunen, <a href="/A286157/b286157.txt">Table of n, a(n) for n = 1..10585; the first 145 antidiagonals of array</a>
%F A286157 A(n,k) = A286156(k,n).
%e A286157 The top left 15 X 15 corner of the array:
%e A286157 1, 3, 6, 10, 15, 21, 28, 36, 45, 55, 66, 78, 91, 105, 120
%e A286157 2, 1, 4, 3, 7, 6, 11, 10, 16, 15, 22, 21, 29, 28, 37
%e A286157 2, 5, 1, 4, 8, 3, 7, 12, 6, 11, 17, 10, 16, 23, 15
%e A286157 2, 5, 9, 1, 4, 8, 13, 3, 7, 12, 18, 6, 11, 17, 24
%e A286157 2, 5, 9, 14, 1, 4, 8, 13, 19, 3, 7, 12, 18, 25, 6
%e A286157 2, 5, 9, 14, 20, 1, 4, 8, 13, 19, 26, 3, 7, 12, 18
%e A286157 2, 5, 9, 14, 20, 27, 1, 4, 8, 13, 19, 26, 34, 3, 7
%e A286157 2, 5, 9, 14, 20, 27, 35, 1, 4, 8, 13, 19, 26, 34, 43
%e A286157 2, 5, 9, 14, 20, 27, 35, 44, 1, 4, 8, 13, 19, 26, 34
%e A286157 2, 5, 9, 14, 20, 27, 35, 44, 54, 1, 4, 8, 13, 19, 26
%e A286157 2, 5, 9, 14, 20, 27, 35, 44, 54, 65, 1, 4, 8, 13, 19
%e A286157 2, 5, 9, 14, 20, 27, 35, 44, 54, 65, 77, 1, 4, 8, 13
%e A286157 2, 5, 9, 14, 20, 27, 35, 44, 54, 65, 77, 90, 1, 4, 8
%e A286157 2, 5, 9, 14, 20, 27, 35, 44, 54, 65, 77, 90, 104, 1, 4
%e A286157 2, 5, 9, 14, 20, 27, 35, 44, 54, 65, 77, 90, 104, 119, 1
%t A286157 Map[((#1 + #2)^2 + 3 #1 + #2)/2 & @@ # & /@ Reverse@ # &, Table[Function[m, Reverse@ QuotientRemainder[m, k]][n - k + 1], {n, 14}, {k, n, 1, -1}]] // Flatten (* _Michael De Vlieger_, May 20 2017 *)
%o A286157 (Scheme) (define (A286157 n) (A286156bi (A004736 n) (A002260 n))) ;; For A286156bi see A286156.
%o A286157 (Python)
%o A286157 def T(a, b): return ((a + b)**2 + 3*a + b)//2
%o A286157 def A(n, k): return T(n%k, int(n//k))
%o A286157 for n in range(1, 21): print([A(n - k + 1, k) for k in range(1, n + 1)]) # _Indranil Ghosh_, May 20 2017
%Y A286157 Transpose: A286156.
%K A286157 nonn,tabl
%O A286157 1,2
%A A286157 _Antti Karttunen_, May 04 2017