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A169783 Number of solutions to a^2+b^2+4*c^2=n. 2
1, 4, 4, 0, 6, 16, 8, 0, 12, 20, 8, 0, 8, 16, 16, 0, 6, 32, 12, 0, 24, 32, 8, 0, 24, 20, 24, 0, 0, 48, 16, 0, 12, 32, 16, 0, 30, 16, 24, 0, 24, 64, 16, 0, 24, 48, 16, 0, 8, 36, 28, 0, 24, 48, 32, 0, 48, 32, 8, 0, 0, 48, 32, 0, 6, 64, 32, 0, 48, 64, 16, 0, 36, 32, 40, 0, 24, 64, 16, 0, 24, 68 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..81.

MAPLE

t0:=Array(0..10000, 0); M:=15;

for i from -M to M do for j from -M to M do for k from -M to M do

t1:=i^2+j^2+4*k^2; t0[t1]:=t0[t1]+1; od: od: od:

[seq(t0[i], i=0..100)];

CROSSREFS

x^2+y^2+k*z^2: A005875, A014455, A034933, A169784.

Sequence in context: A228048 A016705 A245592 * A133657 A121455 A227033

Adjacent sequences:  A169780 A169781 A169782 * A169784 A169785 A169786

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, May 12 2010

STATUS

approved

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Last modified May 29 12:56 EDT 2017. Contains 287246 sequences.