A016987 - OEIS

%I #17 Sep 08 2022 08:44:41

%S 0,823543,105413504,1801088541,13492928512,64339296875,230539333248,

%T 678223072849,1727094849536,3938980639167,8235430000000,

%U 16048523266853,29509034655744,51676101935731

%N a(n) = (7*n)^7.

%C a(n) = A155955(n,7) for n > 6. - _Reinhard Zumkeller_, Jan 31 2009

%H Vincenzo Librandi, <a href="/A016987/b016987.txt">Table of n, a(n) for n = 0..1000</a>

%H <a href="/index/Rec#order_08">Index entries for linear recurrences with constant coefficients</a>, signature (8, -28, 56, -70, 56, -28, 8, -1).

%F a(n) = 8*a(n-1) - 28*a(n-2) + 56*a(n-3) - 70*a(n-4) + 56*a(n-5) - 28*a(n-6) + 8*a(n-7) - a(n-8); a(0)=0, a(1)=823543, a(2)=105413504, a(3)=1801088541, a(4)=13492928512, a(5)=64339296875, a(6)=230539333248, a(7)=678223072849. - _Harvey P. Dale_, Apr 01 2013

%t (7*Range[0,20])^7 (* or *) LinearRecurrence[{8,-28,56,-70,56,-28,8,-1},{0,823543,105413504,1801088541,13492928512,64339296875,230539333248,678223072849},20] (* _Harvey P. Dale_, Apr 01 2013 *)

%o (Magma) [(7*n)^7: n in [0..25]]; // _Vincenzo Librandi_, Jun 18 2011

%K nonn,easy

%O 0,2

%A _N. J. A. Sloane_