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Numbers that are the sum of distinct odd positive squares.
1

%I #4 Jul 26 2017 09:31:47

%S 1,9,10,25,26,34,35,49,50,58,59,74,75,81,82,83,84,90,91,106,107,115,

%T 116,121,122,130,131,139,140,146,147,155,156,164,165,169,170,171,178,

%U 179,180,194,195,196,202,203,204,205,211,212,218,219,225,226,227,228,234,235,236,237,243,244,250,251,252,253

%N Numbers that are the sum of distinct odd positive squares.

%C Complement of A167703.

%C 1922 is the largest of positive integers not in this sequence.

%H <a href="/index/Su#ssq">Index entries for sequences related to sums of squares</a>

%H <a href="/index/Ce#CENTRALCUBE">Index entries for sequences related to centered polygonal numbers</a>

%e 139 is in the sequence because 139 = 9 + 49 + 81 = 3^2 + 7^2 + 9^2.

%t max = 253; f[x_] := Product[1 + x^(2 k + 1)^2, {k, 0, 10}]; Exponent[#, x] & /@ List @@ Normal[Series[f[x], {x, 0, max}]] // Rest

%Y Cf. A003995, A016754, A097269, A167700, A167703.

%K nonn

%O 1,2

%A _Ilya Gutkovskiy_, Jul 25 2017