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A064765 a(n) is the smallest number such that for, all m<n, both a(n)*a(m) and a(n)+a(m) are nonsquares. 0

%I

%S 1,2,5,6,12,17,21,22,26,29,33,39,40,46,51,53,56,57,66,73,77,85,86,89,

%T 97,101,102,106,114,117,131,133,134,135,137,141,146,149,151,161,165,

%U 166,176,177,181,182,197,201,202,206,209,211,214,221,229,231,237,241,246

%N a(n) is the smallest number such that for, all m<n, both a(n)*a(m) and a(n)+a(m) are nonsquares.

%C No number occurs more than once in the sequence because if a(n)=m then if m occurs again then a(n)*m=m^2. a(n) is always bigger than a(n-1) because all numbers less than a(n-1) have been checked to see if they make a square and if any do then because of the uniqueness of each value of a(n) then they must have already occurred in the sequence previously.

%e a(4) = 6 because a(1)*6 = 6, a(2)*6 = 12, a(3)*6 = 30 and a(1)+6 = 7, a(2)+6 = 8, a(3)+6=11, all nonsquares

%K nonn

%O 1,2

%A Jonathan Ayres (jonathan.ayres(AT)btinternet.com), Oct 18 2001

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Last modified December 13 03:41 EST 2019. Contains 329968 sequences. (Running on oeis4.)