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%I #7 Jan 22 2014 05:16:37
%S 1,7,5,11,28,14,182,70,2,66,1518,462,1540,616,296,600,1950,750,10,730,
%T 2336,876,2436,996,3154,1162,5698,210,1554,3234,1638,5382,1872,23088,
%U 4368,5934,201,4359,77991,7021,13090,4270,12950,74,12802,76466,16954
%N a(n) is the smallest unused number such that the RMS (Root Mean Square) of a(1) through a(n) is an integer.
%C Actual RMS values are given by A141392
%H Giovanni Resta, <a href="/A141391/b141391.txt">Table of n, a(n) for n = 1..200</a>
%e a(4) = 11. Sqrt(mean(1^2, 7^2, 5^2, k^2)) is an integer for k in {5,11,37}. We have already used 5 for a(3), so 11 is the smallest value available for a(4).
%Y Cf. A141392, A141393, A141394, A140480.
%K nonn
%O 1,2
%A _Andrew Weimholt_, Jun 29 2008