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 A056535 #18 Oct 15 2015 12:23:09 %S A056535 1,2,3,4,7,5,6,12,13,8,9,18,22,19,10,11,25,32,33,26,14,15,31,43,48,44, %T A056535 34,16,17,39,55,63,64,56,40,20,21,47,68,80,86,81,69,49,23,24,54,79,98, %U A056535 107,108,99,82,57,27,28,62,93,116,129,136,130,117,94,65,29,30,72,106 %N A056535 Mapping from the ordering by sum to the ordering by product of the ordered pairs. Inverse permutation to A056534. %C A056535 The last term of the each row r of the triangle is the first term of that row + (tau(r)-1). %C A056535 As an array, T(n,k) is the index of the k-th term of A027750 whose value is n. - _Michel Marcus_, Oct 15 2015 %H A056535 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a> %F A056535 [seq(nthmember(j, A056534), j=1..105)]; %e A056535 As a triangle, sequence begins: %e A056535 1; %e A056535 2, 3; %e A056535 4, 7, 5; %e A056535 6, 12, 13, 8; %e A056535 9, 18, 22, 19, 10; %e A056535 ... %e A056535 As an array, sequence begins: %e A056535 1, 2, 4, 6, 9, 11, 15, ... %e A056535 3, 7, 12, 18, 25, 31, 39, ... %e A056535 5, 13, 22, 32, 43, 55, 68, ... %e A056535 8, 19, 33, 48, 63, 80, 98, ... %e A056535 10, 26, 44, 64, 86, 107, 129, ... %e A056535 ... %p A056535 Maple procedure nthmember given in A054426. %t A056535 a[n_] := If[p = Position[A056534, n]; p != {}, p[[1, 1]], 0]; (* _Jean-François Alcover_, Aug 20 2013 *) %Y A056535 A056535[A000217[i]] = A056535[A000217[i-1]+1]+A000005[i]-1, for all i >= 1. %Y A056535 Left edge: A054519, Right edge: A006218. %K A056535 nonn,tabl %O A056535 1,2 %A A056535 _Antti Karttunen_, Jun 20 2000