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%I #6 Jul 19 2017 20:20:29
%S 0,1,5,6,14,15,19,20,30,31,35,36,44,45,49,50,55,56,60,61,69,70,74,75,
%T 85,86,90,91,92,96,97,99,100,104,105,106,110,111,121,122,126,127,135,
%U 136,140,141,145,146,147,151,152,154,155,159,160,161,165,166,170,171,175,176,177,181,182,184,185,189,190,191,195,196,200
%N Numbers that are the sum of distinct square pyramidal numbers (A000330).
%C It appears that 1528 is the largest of 306 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/Ps#pyramidal_numbers">Index to sequences related to pyramidal numbers</a>
%F Exponents in expansion of Product_{k>=1} (1 + x^(k*(k+1)*(2*k+1)/6)).
%e 20 is in the sequence because 20 = 1 + 5 + 14 = 1^2 + 1^2 + 2^2 + 1^2 + 2^2 + 3^2.
%t max = 200; f[x_] := Product[1 + x^(k (k + 1) (2 k + 1)/6), {k, 1, 10}]; Exponent[#, x] & /@ List @@ Normal[Series[f[x], {x, 0, max}]]
%Y Cf. A000330, A003995.
%K nonn
%O 1,3
%A _Ilya Gutkovskiy_, Jul 14 2017
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