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a(n) = 30*n + 19.
2

%I #34 Dec 08 2024 14:17:15

%S 19,49,79,109,139,169,199,229,259,289,319,349,379,409,439,469,499,529,

%T 559,589,619,649,679,709,739,769,799,829,859,889,919,949,979,1009,

%U 1039,1069,1099,1129,1159,1189,1219,1249,1279,1309,1339,1369,1399,1429,1459,1489

%N a(n) = 30*n + 19.

%H Vincenzo Librandi, <a href="/A156376/b156376.txt">Table of n, a(n) for n = 0..1000</a>

%H <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (2,-1).

%F a(n) = 2*a(n-1) - a(n-2).

%F G.f.: (19+11*x)/(x-1)^2.

%F Sum_{n>=0} a(n)/(16*(n+1)^3*(2*n+1)*binomial(2*n+1,n)^2) = zeta(3). - _Daniel Suteu_, Oct 31 2017

%F E.g.f.: exp(x)*(19 + 30*x). - _Elmo R. Oliveira_, Dec 08 2024

%t Range[19, 7000, 30] (* _Vladimir Joseph Stephan Orlovsky_, Jul 13 2011 *)

%t LinearRecurrence[{2, -1}, {19, 49}, 50] (* _Vincenzo Librandi_, Mar 01 2012 *)

%o (Magma) I:=[19, 49]; [n le 2 select I[n] else 2*Self(n-1)-Self(n-2): n in [1..50]]; // _Vincenzo Librandi_, Mar 01 2012

%K nonn,easy,changed

%O 0,1

%A _Vincenzo Librandi_, Aug 12 2009

%E Offset corrected by _R. J. Mathar_, Oct 12 2009