

A195023


a(n) = 14*n^2  4*n.


10



0, 10, 48, 114, 208, 330, 480, 658, 864, 1098, 1360, 1650, 1968, 2314, 2688, 3090, 3520, 3978, 4464, 4978, 5520, 6090, 6688, 7314, 7968, 8650, 9360, 10098, 10864, 11658, 12480, 13330, 14208, 15114, 16048, 17010, 18000, 19018, 20064, 21138, 22240
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OFFSET

0,2


COMMENTS

Sequence found by reading the line from 0, in the direction 0, 10, ..., in the Pythagorean spiral whose edges have length A195019 and whose vertices are the numbers A195020. This is the one of the semiaxis of the square spiral, which is related to the primitive Pythagorean triple [3, 4, 5].


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(n) = 2*A135703(n).  Bruno Berselli, Oct 13 2011
From Colin Barker, Apr 09 2012: (Start)
a(n) = 3*a(n1)  3*a(n2) + a(n3).
G.f.: 2*x*(5+9*x)/(1x)^3. (End)


MATHEMATICA

Table[14n^24n, {n, 0, 40}] (* or *) LinearRecurrence[{3, 3, 1}, {0, 10, 48}, 50] (* Harvey P. Dale, Sep 05 2012 *)


PROG

(MAGMA) [14*n^2  4*n: n in [0..50]]; // Vincenzo Librandi, Oct 14 2011
(PARI) a(n)=14*n^24*n \\ Charles R Greathouse IV, Apr 10 2012


CROSSREFS

Cf. A144555, A152760, A195019, A195020, A195024, A195320, A185019, A193053, A198017.
Sequence in context: A121075 A121073 A210371 * A277229 A163724 A271638
Adjacent sequences: A195020 A195021 A195022 * A195024 A195025 A195026


KEYWORD

nonn,easy


AUTHOR

Omar E. Pol, Oct 13 2011


EXTENSIONS

Corrected by Vincenzo Librandi, Oct 14 2011


STATUS

approved



