%N Basic numbers used in Sedgewick-Incerpi upper bound for shell sort.
%D D. E. Knuth, The Art of Computer Programming, Vol. 3, Sorting and Searching, 2nd ed, section 5.2.1, p. 91.
%H Robert Sedgewick, <a href="http://www.cs.princeton.edu/~rs/talks/shellsort.ps">Analysis of shellsort and related algorithms</a>, Fourth European Symposium on Algorithms, Barcelona, September, 1996.
%H <a href="/index/So#sorting">Index entries for sequences related to sorting</a>
%F a(n) is the smallest number >= 2.5^n that is relatively prime to all previous terms in the sequence.
%e 2.5^4 = 39.0625, and 41 is the next integer that is relatively prime to 3, 7 and 16.
%Y Cf. A036569.
%A _N. J. A. Sloane_
%E Better description and more terms from _Jud McCranie_, Jan 05 2001