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 A344009 #21 Jun 09 2021 16:50:27 %S A344009 1,2,3,4,5,7,6,8,9,13,10,11,14,15,19,12,16,17,21,25,27,18,20,23,26,29, %T A344009 31,39,22,24,28,33,37,41,43,49,30,32,35,38,44,45,51,61,63,34,36,40,47, %U A344009 50,55,62,65,67,79,42,46,52,53,57,64,69,73,85,87,91,48,54,56,66,68,74,75,86,89,99,103,109 %N A344009 The Tchoukaillon array of order infinity read by downward antidiagonals. %D A344009 D. E. Knuth, Bipartite Matching, The Art of Computer Programming, Vol. 4, Pre-fascicle 14A, June 8, 2021, http://cs.stanford.edu/~knuth/fasc14a.ps.gz. See Sect. 7.5.1, Exercise 13. %H A344009 D. E. Knuth, <a href="/A344009/a344009_1.txt">The first 32 rows</a> %e A344009 The array begins: %e A344009 1, 2, 4, 6, 10, 12, 18, 22, 30, 34, 42, 48, 58, 60, 78, 82, 102, 108, 118, 132, 150, 154, 174, 192, 210, 214, 240, 258, 274, 282, 322, 330, ... %e A344009 3, 5, 8, 11, 16, 20, 24, 32, 36, 46, 54, 59, 72, 80, 90, 106, 114, 120, 142, 152, 168, 180, 198, 212, 228, 252, 270, 276, 318, 324, 334, ... %e A344009 7, 9, 14, 17, 23, 28, 35, 40, 52, 56, 70, 76, 84, 94, 112, 116, 138, 144, 162, 172, 196, 202, 222, 234, 262, 272, 298, 320, 332, 342, ... %e A344009 13, 15, 21, 26, 33, 38, 47, 53, 66, 71, 83, 92, 107, 113, 130, 140, 156, 166, 190, 200, 216, 232, 256, 264, 288, 312, 328, 336, 378, ... %e A344009 19, 25, 29, 37, 44, 50, 57, 68, 77, 88, 96, 110, 119, 136, 148, 160, 178, 197, 204, 226, 250, 260, 275, 294, 323, 335, 358, 380, ... %e A344009 27, 31, 41, 45, 55, 64, 74, 81, 95, 100, 117, 126, 143, 155, 167, 179, 203, 208, 238, 251, 268, 286, 316, 326, 354, 359, 406, ... %e A344009 39, 43, 51, 62, 69, 75, 93, 98, 115, 124, 137, 153, 164, 176, 201, 206, 236, 239, 263, 280, 300, 317, 348, 356, 392, 407, %e A344009 ... %e A344009 49, 61, 65, 73, 86, 97, 104, 122, 131, 146, 158, 173, 191, 205, 215, 237, 257, 278, 292, 310, 333, 352, 366, 400, 417, ... %e A344009 ... %e A344009 The initial antidiagonals are: %e A344009 [1], %e A344009 [2, 3], %e A344009 [4, 5, 7], %e A344009 [6, 8, 9, 13], %e A344009 [10, 11, 14, 15, 19], %e A344009 [12, 16, 17, 21, 25, 27], %e A344009 [18, 20, 23, 26, 29, 31, 39], %e A344009 [22, 24, 28, 33, 37, 41, 43, 49], %e A344009 [30, 32, 35, 38, 44, 45, 51, 61, 63], %e A344009 [34, 36, 40, 47, 50, 55, 62, 65, 67, 79], %e A344009 [42, 46, 52, 53, 57, 64, 69, 73, 85, 87, 91], %e A344009 [48, 54, 56, 66, 68, 74, 75, 86, 89, 99, 103, 109], %e A344009 [58, 59, 70, 71, 77, 81, 93, 97, 101, 105, 121, 123, 133], %e A344009 [60, 72, 76, 83, 88, 95, 98, 104, 111, 125, 127, 135, 139, 147], %e A344009 ... %Y A344009 Rows: A002491, A344010, A344011, ... %Y A344009 Columns: A000960, A100287, A344012, ... %K A344009 nonn,tabl %O A344009 1,2 %A A344009 _N. J. A. Sloane_, Jun 09 2021, based on an email from _Don Knuth_, Jun 08 2021