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 A097286 #15 May 10 2025 11:28:50
%S A097286 1,3,2,7,5,4,13,9,6,8,21,15,11,10,14,31,23,17,12,16,22,43,33,25,19,18,
%T A097286 24,32,57,45,35,27,20,26,34,44,73,59,47,37,29,28,36,46,58,91,75,61,49,
%U A097286 39,30,38,48,60,74,111,93,77,63,51,41,40,50,62,76,92,133,113,95,79,65,53,42,52,64,78,94,112
%N A097286 Rectangular array T by descending antidiagonals: T(n,k) = rank of k-th n in A097285.
%C A097286 As a sequence, this is a permutation of the natural numbers.
%e A097286 Corner:
%e A097286 1 3 7 13 21 31 43 57 73 91 111
%e A097286 2 5 9 15 23 33 45 59 75 93 113
%e A097286 4 6 11 17 25 35 47 61 77 95 115
%e A097286 8 10 12 19 27 37 49 63 79 97 117
%e A097286 14 16 18 20 29 39 51 65 81 99 119
%e A097286 22 24 26 28 30 41 53 67 83 101 121
%e A097286 32 34 36 38 40 42 55 69 85 103 123
%e A097286 44 46 48 50 52 54 56 71 87 105 125
%e A097286 58 60 62 64 66 68 70 72 89 107 127
%e A097286 74 76 78 80 82 84 86 88 90 109 129
%e A097286 92 94 96 98 100 102 104 106 108 110 131
%t A097286 s = {1, 2}; Do[s = Join[s, Riffle[Range[n - 1], n], {n}], {n, 3, 12}];
%t A097286 Grid[Table[Flatten[Position[s, n]], {n, 1, 12}]] (* _Clark Kimberling_, May 09 2025 *)
%Y A097286 Cf. A002061 (row 1), A014206 (column 1), A097285.
%K A097286 nonn,tabl
%O A097286 1,2
%A A097286 _Clark Kimberling_, Aug 05 2004