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A007533 (5n+1)^2 + 4n+1.
(Formerly M2162)
2

%I M2162

%S 2,41,130,269,458,697,986,1325,1714,2153,2642,3181,3770,4409,5098,

%T 5837,6626,7465,8354,9293,10282,11321,12410,13549,14738,15977,17266,

%U 18605,19994,21433,22922,24461,26050,27689,29378

%N (5n+1)^2 + 4n+1.

%C Also, numbers of the form (3n+1)^2+(4n+1)^2. - _Bruno Berselli_, Dec 11 2011

%D W. Sierpiński, Elementary Theory of Numbers. Państ. Wydaw. Nauk., Warsaw, 1964, p. 323.

%D N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

%H Vincenzo Librandi, <a href="/A007533/b007533.txt">Table of n, a(n) for n = 0..1000</a>

%H W. Sierpiński, <a href="http://matwbn.icm.edu.pl/kstresc.php?tom=42&amp;wyd=10">Elementary Theory of Numbers</a>, Warszawa 1964.

%H <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (3,-3,1).

%F a(n) = 25n^2+14n+2. G.f.: (2+35*x+13*x^2)/(1-x)^3. - _Bruno Berselli_, Dec 11 2011

%t Table[25n^2+14n+2,{n,0,40}] (* or *) LinearRecurrence[{3,-3,1},{2,41,130},40] (* _Harvey P. Dale_, Dec 18 2013 *)

%o (MAGMA) [(5*n+1)^2 + 4*n+1: n in [0..40]]; // _Vincenzo Librandi_, May 02 2011

%o (PARI) a(n)=25*n^2 + 14*n + 2 \\ _Charles R Greathouse IV_, May 02 2011

%K nonn,easy

%O 0,1

%A _N. J. A. Sloane_, _Robert G. Wilson v_

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Last modified May 18 19:58 EDT 2021. Contains 344002 sequences. (Running on oeis4.)