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