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0, 30, 120, 270, 480, 750, 1080, 1470, 1920, 2430, 3000, 3630, 4320, 5070, 5880, 6750, 7680, 8670, 9720, 10830, 12000, 13230, 14520, 15870, 17280, 18750, 20280, 21870, 23520, 25230, 27000, 28830, 30720, 32670, 34680, 36750, 38880, 41070, 43320, 45630, 48000
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OFFSET
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0,2
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COMMENTS
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Sequence found by reading the line from 0, in the direction 0, 30,..., in the square spiral whose vertices are the generalized 17-gonal numbers. - Omar E. Pol, Jul 03 2014
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LINKS
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FORMULA
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G.f.: 30*x*(1 + x)/(1 - x)^3.
a(n) = 3*a(n-1) -3*a(n-2) +a(n-3) for n>2.
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MAPLE
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MATHEMATICA
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Table[30 n^2, {n, 0, 40}]
CoefficientList[Series[30x (1+x)/(1-x)^3, {x, 0, 50}], x] (* or *) LinearRecurrence[ {3, -3, 1}, {0, 30, 120}, 50] (* Harvey P. Dale, Dec 02 2021 *)
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PROG
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(Magma) [30*n^2: n in [0..40]];
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CROSSREFS
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Cf. similar sequences listed in A244630.
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KEYWORD
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nonn,easy
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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