A288838 - OEIS

%I #16 May 15 2022 18:29:26

%S 54,729,6075,40095,229635,1194102,5786802,26572050,116917020,

%T 496897335,2051893701,8269753401,32643763425,126557359740,

%U 482984209620,1817776934388,6757388169138,24843338857125,90429753439935,326206114635555,1167092987918319,4144371018322194

%N a(n) = (1/4!)*3^(n+2)*(n+7)*(n+2)*(n+1)*(n).

%H <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (15,-90,270,-405,243).

%F O.g.f.: z*3^3*(2-3*z)/(1-3*z)^5.

%F a(n) = A287768(n+7,9).

%t Table[1/4! 3^(n+2) (n+7)(n+2)(n+1)n,{n,30}] (* or *) LinearRecurrence[{15,-90,270,-405,243},{54,729,6075,40095,229635},30] (* _Harvey P. Dale_, May 15 2022 *)

%o (PARI) a(n)=3^n*3*n*(n+1)*(n+2)*(n+7)/8 \\ _Charles R Greathouse IV_, Jun 19 2017

%Y Column k=9 of A287768.

%Y Cf. A288834, A288835, A288836.

%K nonn,easy

%O 1,1

%A _Gregory Gerard Wojnar_, Jun 17 2017