notes after first iteration = when the increment reduces to you will get the following lists ( ( ( now if we analyse the first sub lists where increment was and then second sub lists where increment was we can see that in the second set of listswe are comparing and sorting again which we had already sorted before in the previous sub list sowe should choose the value of in such way that in every iterations we get almost different elements in the sub lists to compare and sort there are proven and recommended ways for generating the increment sequences some of them have been discussed below donald shell has suggested ht / hkhk+ / which give the increment series asn/ / hibbard suggested the sequence of increment as - another way for calculating increment suggested by knuth and we have used this method for generating the increments in this tutorial hi hi hi + and stops at htwhen ht+ > which gives the increment series as ht task discuss insertion sorting techniques other than thesethere are many series which have been empirically found and perform well examplewe will take an example to illustrate shell sort let the list be - and the increment values using knuth formula we get are when increment is we get the following sub lists and the elements are divided among the sub lists in the following ways every kth element of the list starting with the index will be in the sub list lovely professional university