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A194268
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a(n) = 8*n^2 + 7*n + 1.
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5
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1, 16, 47, 94, 157, 236, 331, 442, 569, 712, 871, 1046, 1237, 1444, 1667, 1906, 2161, 2432, 2719, 3022, 3341, 3676, 4027, 4394, 4777, 5176, 5591, 6022, 6469, 6932, 7411, 7906, 8417, 8944, 9487, 10046, 10621, 11212, 11819, 12442, 13081, 13736, 14407
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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 1, in the direction 1, 16,..., in the square spiral whose vertices are the triangular numbers A000217.
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LINKS
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FORMULA
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a(0)=1, a(1)=16, a(2)=47, a(n)=3*a(n-1)-3*a(n-2)+a(n-3). - Harvey P. Dale, Apr 06 2014
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MAPLE
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MATHEMATICA
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Table[8n^2+7n+1, {n, 0, 50}] (* or *) LinearRecurrence[{3, -3, 1}, {1, 16, 47}, 50] (* Harvey P. Dale, Apr 06 2014 *)
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PROG
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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STATUS
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approved
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