cp's OEIS Frontend

A244804 The 300-degree spoke (or ray) of a hexagonal spiral of Ulam.

%I A244804 #21 Feb 25 2023 20:57:30
%S A244804 1,14,51,112,197,306,439,596,777,982,1211,1464,1741,2042,2367,2716,
%T A244804 3089,3486,3907,4352,4821,5314,5831,6372,6937,7526,8139,8776,9437,
%U A244804 10122,10831,11564,12321,13102,13907,14736,15589,16466,17367,18292,19241,20214,21211,22232,23277,24346,25439
%N A244804 The 300-degree spoke (or ray) of a hexagonal spiral of Ulam.
%H A244804 Colin Barker, <a href="/A244804/b244804.txt">Table of n, a(n) for n = 1..1000</a>
%H A244804 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (3,-3,1).
%F A244804 See A056105 example section for its formula.
%F A244804 From _Colin Barker_, Dec 12 2016: (Start)
%F A244804 a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3) for n>3.
%F A244804 G.f.: x*(1 + 11*x + 12*x^2) / (1 - x)^3.
%F A244804 (End)
%e A244804 See A056105 example section for its diagram.
%p A244804 A244804:=n->12*n^2 - 23*n + 12: seq(A244804(n), n=1..50); # _Wesley Ivan Hurt_, Jul 06 2014
%t A244804 f[n_] := 12n^2 - 23n + 12; Array[f, 47]
%o A244804 (PARI) vector(50, n, 12*n^2 - 23*n + 12) \\ _Michel Marcus_, Jul 06 2014
%o A244804 (PARI) Vec(x*(1 + 11*x + 12*x^2) / (1 - x)^3 + O(x^50)) \\ _Colin Barker_, Dec 12 2016
%o A244804 (Magma) [ 12*n^2 - 23*n + 12 : n in [1..50] ]; // _Wesley Ivan Hurt_, Jul 06 2014
%Y A244804 Cf. A056105, A244802, A056106, A244803, A056107, A056108, A244805, A056109, A244806, A003215, A033577.
%K A244804 nonn,easy
%O A244804 1,2
%A A244804 _Robert G. Wilson v_, Jul 06 2014