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 A241957 #40 Feb 07 2017 15:55:01 %S A241957 1,3,5,7,11,9,15,23,19,13,31,47,39,27,17,63,95,79,55,35,21,127,191, %T A241957 159,111,71,43,25,255,383,319,223,143,87,51,29,511,767,639,447,287, %U A241957 175,103,59,33,1023,1535,1279,895,575,351,207,119,67,37 %N A241957 Rectangular array A read by upward antidiagonals in which the entry in row n and column k is defined by A(n,k) = 2^n*(2*k - 1) - 1, n,k >= 1. %C A241957 The sequence is a permutation of the odd natural numbers, since A(n,k) = 2*A054582(n-1,k-1) - 1 and A054582 is a permutation of the natural numbers. %C A241957 For j a natural number, 2*j - 1 appears in row A001511(j) of A. %C A241957 This is the square array A075300 with the first row omitted. - _Peter Bala_, Feb 07 2017 %H A241957 Vincenzo Librandi, <a href="/A241957/b241957.txt">Rows n = 0..50, flattened</a> %H A241957 <a href="https://oeis.org/wiki/Index_to_OEIS:_Section_3#3x1">Index entries for sequences related to 3x+1 (or Collatz) problem</a>. %F A241957 A(n,k) = 2*A054582(n-1,k-1) - 1. %e A241957 Array begins: %e A241957 . 1 5 9 13 17 21 25 29 33 37 %e A241957 . 3 11 19 27 35 43 51 59 67 75 %e A241957 . 7 23 39 55 71 87 103 119 135 151 %e A241957 . 15 47 79 111 143 175 207 239 271 303 %e A241957 . 31 95 159 223 287 351 415 479 543 607 %e A241957 . 63 191 319 447 575 703 831 959 1087 1215 %e A241957 . 127 383 639 895 1151 1407 1663 1919 2175 2431 %e A241957 . 255 767 1279 1791 2303 2815 3327 3839 4351 4863 %e A241957 . 511 1535 2559 3583 4607 5631 6655 7679 8703 9727 %e A241957 . 1023 3071 5119 7167 9215 11263 13311 15359 17407 19455 %t A241957 (* Array: *) %t A241957 Grid[Table[2^n*(2*k - 1) - 1, {n, 10}, {k, 10}]] %t A241957 (* Array antidiagonals flattened: *) %t A241957 Flatten[Table[2^(n - k + 1)*(2*k - 1) - 1, {n, 10}, {k, n}]] %Y A241957 Cf. A016813, A017101 (rows 1 and 2). %Y A241957 Cf. A000225, A083329, A153894, A086224, A052996, etc. (columns 1-5). %Y A241957 Cf. A005408 (odd natural numbers), A054582. %Y A241957 Cf. A075300. %K A241957 nonn,tabl,easy %O A241957 1,2 %A A241957 _L. Edson Jeffery_, Aug 09 2014