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 A385342 #13 Jul 23 2025 16:13:59 %S A385342 1,2,2,3,1,3,4,6,6,4,5,8,1,8,5,6,10,12,12,10,6,7,12,15,1,15,3,7,8,14, %T A385342 18,20,20,2,14,8,9,16,21,24,1,24,21,4,9,10,18,24,28,30,30,28,24,18,10, %U A385342 11,20,27,32,35,1,35,2,27,5,11,12,22,30,36,40,42,42,40,36,30,22,12 %N A385342 Square array A(n,k) read by descending antidiagonals, where each row n starts with an ordered list of positive integers then we swap A(n,k) with the number in the position A(n, A(n,k*n)). %C A385342 The lower triangular array is the multiplication table. %C A385342 The second row is A073675. %C A385342 The first superdiagonal and the first subdiagonal are both A002378. %e A385342 The square array begins: %e A385342 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, ... %e A385342 2, 1, 6, 8, 10, 3, 14, 4, 18, 5, 22, 24, 26, 7, 30, 32, 34, ... %e A385342 3, 6, 1, 12, 15, 2, 21, 24, 27, 30, 33, 4, 39, 42, 5, 48, 51, ... %e A385342 4, 8, 12, 1, 20, 24, 28, 2, 36, 40, 44, 3, 52, 56, 60, 64, 68, ... %e A385342 5, 10, 15, 20, 1, 30, 35, 40, 45, 2, 55, 60, 65, 70, 3, 80, 85, ... %e A385342 6, 12, 18, 24, 30, 1, 42, 48, 54, 60, 66, 2, 78, 84, 90, 96, 102, ... %e A385342 7, 14, 21, 28, 35, 42, 1, 56, 63, 70, 77, 84, 91, 2, 105, 112, 119, ... %e A385342 8, 16, 24, 32, 40, 48, 56, 1, 72, 80, 88, 96, 104, 112, 120, 2, 136, ... %e A385342 9, 18, 27, 36, 45, 54, 63, 72, 1, 90, 99, 108, 117, 126, 135, 144, 153, ... %e A385342 10, 20, 30, 40, 50, 60, 70, 80, 90, 1, 110, 120, 130, 140, 150, 160, 170, ... %Y A385342 Cf. A002378, A073675. %K A385342 nonn,tabl %O A385342 1,2 %A A385342 _Ali Sada_, Jun 26 2025