

A194268


8*n^2 + 7*n + 1.


5



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

0,2


COMMENTS

Sequence found by reading the line from 1, in the direction 1, 16,..., in the square spiral whose vertices are the triangular numbers A000217.


LINKS

Vincenzo Librandi, Table of n, a(n) for n = 0..10000
Index entries for linear recurrences with constant coefficients, signature (3, 3, 1).


FORMULA

a(0)=1, a(1)=16, a(2)=47, a(n)=3*a(n1)3*a(n2)+a(n3).  Harvey P. Dale, Apr 06 2014


MAPLE

A194268:=n>8*n^2+7*n+1: seq(A194268(n), n=0..50); # Wesley Ivan Hurt, Jul 15 2014


MATHEMATICA

Table[8n^2+7n+1, {n, 0, 50}] (* or *) LinearRecurrence[{3, 3, 1}, {1, 16, 47}, 50] (* Harvey P. Dale, Apr 06 2014 *)


PROG

(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


CROSSREFS

Cf. A014634, A069129, A051870, A139098, A194431.
Sequence in context: A253350 A204616 A204800 * A292171 A204609 A233063
Adjacent sequences: A194265 A194266 A194267 * A194269 A194270 A194271


KEYWORD

nonn,easy


AUTHOR

Omar E. Pol, Sep 05 2011


STATUS

approved



