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Partial sums of A162255.
3

%I #11 Sep 08 2022 08:45:47

%S 3,5,11,15,27,35,59,75,123,155,251,315,507,635,1019,1275,2043,2555,

%T 4091,5115,8187,10235,16379,20475,32763,40955,65531,81915,131067,

%U 163835,262139,327675,524283,655355,1048571,1310715,2097147,2621435,4194299

%N Partial sums of A162255.

%C Apparently a(n) = A094958(n+4)-5.

%H G. C. Greubel, <a href="/A164053/b164053.txt">Table of n, a(n) for n = 1..1000</a>

%H <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (1, 2, -2).

%F a(n) = 2*a(n-2) + 5 for n > 2; a(1) = 3, a(2) = 5.

%F a(n) = (13 - 3*(-1)^n)*2^(1/4*(2*n -1 +(-1)^n))/2 - 5.

%F G.f.: x*(3+2*x)/(1-x-2*x^2+2*x^3).

%F a(1)=3, a(2)=5, a(3)=11, a(n)=a(n-1)+2*a(n-2)-2*a(n-3). - _Harvey P. Dale_, Aug 28 2012

%t Accumulate[LinearRecurrence[{0,2},{3,2},50]] (* or *) LinearRecurrence[ {1,2,-2},{3,5,11},50] (* _Harvey P. Dale_, Aug 28 2012 *)

%o (Magma) T:=[ n le 2 select 4-n else 2*Self(n-2): n in [1..39] ]; [ n eq 1 select T[1] else Self(n-1)+T[n]: n in [1..#T]];

%o (PARI) x='x+O('x^50); Vec(x*(3+2*x)/(1-x-2*x^2+2*x^3)) \\ _G. C. Greubel_, Sep 09 2017

%Y Cf. A162255, A094958.

%K nonn

%O 1,1

%A _Klaus Brockhaus_, Aug 08 2009