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One half of the even numbers that are the sum of four nonzero squares.
1

%I #4 May 09 2013 06:59:43

%S 2,5,6,8,9,10,11,13,14,15,17,18,19,20,21,22,23,24,25,26,27,29,30,31,

%T 32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,49,50,51,52,53,54,55,

%U 56,57,58,59,60,61,62,63,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79

%N One half of the even numbers that are the sum of four nonzero squares.

%C These are the even numbers of A000414 divided by 2.

%F a(n) is one half of the n-th even number of the sequence A000414.

%Y Cf. A000414.

%K nonn

%O 1,1

%A _Wolfdieter Lang_, May 09 2013