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a(n) is the least M such that there are n values in 0..M with no two values summing to a square.
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%I #25 Oct 19 2017 10:40:00

%S 0,2,3,5,8,10,11,14,18,20,21,24,26,28,32,34,36,38,40,42,48,52,54,56,

%T 58,60,62,64,72,74,76,78,80,82,84,86,88,99,101,103,105,107,109,111,

%U 114,116,118,129,130,133,135,137,139,141,143,145,152,159,160,163,167

%N a(n) is the least M such that there are n values in 0..M with no two values summing to a square.

%C Examples where the solution is unique:

%C (14,28) 2 4 6 9 11 13 15 17 18 20 22 24 26 28

%C (16,34) 3 5 8 10 12 14 16 18 19 21 23 25 27 29 32 34

%C (17,36) 3 5 8 10 12 14 16 18 19 21 23 25 27 29 32 34 36

%C (18,38) 3 5 8 10 12 14 16 18 19 21 23 25 27 29 32 34 36 38

%C (19,40) 3 5 8 10 12 14 16 18 19 21 23 25 27 29 32 34 36 38 40

%C (20,42) 3 5 8 10 12 14 16 18 19 21 23 25 27 29 32 34 36 38 40 42

%H Rob Pratt, <a href="/A099107/b099107.txt">Table of n, a(n) for n = 1..100</a>

%Y If the numbers are taken from 1..M instead of 0..M, we get A210380.

%K nonn

%O 1,2

%A Jean-Charles Meyrignac (euler(AT)free.fr), Nov 14 2004

%E Definition clarified and sequence extended by _Don Reble_ and _M. F. Hasler_, Jul 08 2014

%E More terms from _Rob Pratt_, Jul 11 2014