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A194268
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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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Vincenzo Librandi, Table of n, a(n) for n = 0..10000
Index entries for linear recurrences with constant coefficients, signature (3, -3, 1).
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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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A194268:=n->8*n^2+7*n+1: seq(A194268(n), n=0..50); # Wesley Ivan Hurt, Jul 15 2014
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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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(Magma) [8*n^2 +7*n + 1: n in [0..50]]; // Vincenzo Librandi, Sep 07 2011
(PARI) a(n)=8*n^2+7*n+1 \\ Charles R Greathouse IV, Oct 07 2015
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CROSSREFS
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Cf. A014634, A069129, A051870, A139098, A194431.
Sequence in context: A253350 A204616 A204800 * A292171 A204609 A233063
Adjacent sequences: A194265 A194266 A194267 * A194269 A194270 A194271
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KEYWORD
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nonn,easy
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AUTHOR
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Omar E. Pol, Sep 05 2011
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STATUS
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approved
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