A020715 - OEIS

%I #21 Dec 07 2024 07:47:40

%S 6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,

%T 30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,

%U 53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79

%N a(n) = n + 6.

%C Pisot sequences E(6,7), P(6,7), T(6,7).

%H Tanya Khovanova, <a href="http://www.tanyakhovanova.com/RecursiveSequences/RecursiveSequences.html">Recursive Sequences</a>.

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

%F a(n) = n + 6.

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

%F From _Elmo R. Oliveira_, Dec 06 2024: (Start)

%F G.f.: (6 - 5*x)/(1 - x)^2.

%F E.g.f.: (6 + x)*exp(x). (End)

%t Range[6,80] (* _Harvey P. Dale_, Jul 18 2023 *)

%o (PARI) a(n)=n+6

%Y See A008776 for definitions of Pisot sequences.

%K nonn,easy

%O 0,1

%A _David W. Wilson_