A064838 - OEIS

%I #16 Nov 18 2022 12:52:36

%S 0,1,9,57,210,585,1355,2769,5156,8945,14669,22985,34678,50681,72079,

%T 100129,136264,182113,239505,310489,397338,502569,628947,779505,

%U 957548,1166673,1410773,1694057,2021054,2396633,2826007,3314753

%N a(n) = A064837(n)/2.

%H Harry J. Smith, <a href="/A064838/b064838.txt">Table of n, a(n) for n = 0..500</a>

%H <a href="/index/Rec#order_07">Index entries for linear recurrences with constant coefficients</a>, signature (5,-9,5,5,-9,5,-1).

%F From _Chai Wah Wu_, Aug 01 2020: (Start)

%F a(n) = 5*a(n-1) - 9*a(n-2) + 5*a(n-3) + 5*a(n-4) - 9*a(n-5) + 5*a(n-6) - a(n-7) for n > 6.

%F G.f.: x*(-x^5 - 2*x^4 + x^3 + 21*x^2 + 4*x + 1)/((x - 1)^6*(x + 1)). (End)

%t LinearRecurrence[{5,-9,5,5,-9,5,-1},{0,1,9,57,210,585,1355},40] (* _Harvey P. Dale_, Nov 18 2022 *)

%o (PARI) { for (n=0, 500, a=(6*n^4 + 30*n^3 - 20*n^2 + 14)*n/30 + n%2; write("b064838.txt", n, " ", a/2) ) } \\ _Harry J. Smith_, Sep 28 2009

%K nonn,easy

%O 0,3

%A _N. J. A. Sloane_, Oct 25 2001

%E Offset changed from 1 to 0 by _Harry J. Smith_, Sep 28 2009