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A010012
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a(0) = 1, a(n) = 22*n^2 + 2 for n>0.
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1
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1, 24, 90, 200, 354, 552, 794, 1080, 1410, 1784, 2202, 2664, 3170, 3720, 4314, 4952, 5634, 6360, 7130, 7944, 8802, 9704, 10650, 11640, 12674, 13752, 14874, 16040, 17250, 18504, 19802, 21144, 22530, 23960, 25434, 26952, 28514, 30120, 31770, 33464, 35202, 36984
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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COMMENTS
| Contribution from Bruno Berselli, Feb 06 2012: (Start)
First trisection of A008259.
Apart from the first term, numbers of the form (r^2+2*s^2)*n^2+2 = (r*n)^2+(s*n-1)^2+(s*n+1)^2: in this case is r=2, s=3. After 1, all terms are in A000408. (End)
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LINKS
| Bruno Berselli, Table of n, a(n) for n = 0..1000
Index to sequences with linear recurrences with constant coefficients, signature (3,-3,1).
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FORMULA
| G.f.: (1+x)*(1+20*x+x^2)/(1-x)^3. - Bruno Berselli, Feb 06 2012
E.g.f.: (x*(x+1)*22+2)*e^x-1. - Gopinath A. R., Feb 14 2012
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MATHEMATICA
| Join[{1}, 22 Range[41]^2 + 2] (* Bruno Berselli, Feb 06 2012 *)
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CROSSREFS
| Cf. A206399.
Sequence in context: A007201 A044211 A044592 * A076799 A055671 A090214
Adjacent sequences: A010009 A010010 A010011 * A010013 A010014 A010015
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KEYWORD
| nonn,easy,changed
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com).
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