|
%I #39 Mar 25 2024 09:59:05
%S 6,8,10,12,14,15,18,22,20,26,21,24,34,27,38,30,28,33,46,32,39,35,40,
%T 58,42,62,45,44,51,48,74,57,52,50,82,56,86,55,60,69,94,54,63,68,65,
%U 106,70,66,72,76,87,118,75,122,93,77,78,80,134,85,92,84
%N Let m = n-th nonsquare = A000037(n); then a(n) = A006255(m).
%H Peter Kagey, <a href="/A233421/b233421.txt">Table of n, a(n) for n = 1..5000</a>
%H William Lowell Putnam Competition, <a href="http://kskedlaya.org/putnam-archive/2013.pdf">Problem A2</a>, 2013.
%H R. L. Graham, <a href="http://www.jstor.org/stable/2689569">Bijection between integers and composites</a>, Problem 1242, Math. Mag., 60 (1987), p. 180. [Note that unless you subscribe to JSTOR this link will only show page 178, which contains a different problem proposed by R. L. Graham. - _N. J. A. Sloane_, Jan 13 2014]
%F a(n) = A006255(A000037(n)). - _Michel Marcus_, Jan 07 2014
%e a(1) = A006255(A000037(1)) = A006255(2) = 6 because 2*3*6 = 6^2.
%e a(2) = A006255(A000037(2)) = A006255(3) = 8 because 3*6*8 = 12^2.
%Y Arguments are numbers that are nonsquares: A000037.
%Y This is A006255 with perfect squares omitted.
%K nonn
%O 1,1
%A _Peter Kagey_, Dec 09 2013
%E Edited by _Michel Marcus_ and _N. J. A. Sloane_, Jan 13 2014
|
