login
a(n) = 8^n-7^n-6^n-5^n-4^n-3^n-2^n.
0

%I #21 Jul 05 2021 15:17:54

%S 3761,77325,896849,8869821,81550961,719926125,6196609169,52439953821,

%T 438516694961,3635082523725,29935019892689,245264010263421,

%U 2001462391659761,16280541150478125,132087583623451409,1069376609438070621,8642407976463949361,69743131733050637325

%N a(n) = 8^n-7^n-6^n-5^n-4^n-3^n-2^n.

%C The sequence starts at n=5 as for n<5 the result is negative. - _Tanya Khovanova_, Jul 05 2021

%H <a href="/index/Rec#order_07">Index entries for linear recurrences with constant coefficients</a>, signature (35,-511,4025,-18424,48860,-69264,40320).

%F G.f.: x^5*(23345280*x^6 -29177136*x^5 +12543396*x^4 -1855156*x^3 -112345*x^2 +54310*x -3761)/((2*x -1)*(3*x -1)*(4*x -1)*(5*x -1)*(6*x -1)*(7*x -1)*(8*x -1)). - _Colin Barker_, Nov 05 2012

%e a(5) = 8^5 - 7^5 - 6^5 - 5^5 - 4^5 - 3^5 - 2^5 = 3761. - _Tanya Khovanova_, Jul 05 2021

%t Array[8^#-7^#-6^#-5^#-4^#-3^#-2^# &, 10, 0]

%t LinearRecurrence[{35,-511,4025,-18424,48860,-69264,40320},{3761,77325,896849,8869821,81550961,719926125,6196609169},20] (* _Harvey P. Dale_, Sep 04 2017 *)

%o (Python)

%o def a(n): return 8**n - 7**n - 6**n - 5**n - 4**n - 3**n - 2**n

%o print([a(n) for n in range(5, 23)]) # _Michael S. Branicky_, Jul 05 2021

%K nonn,easy

%O 5,1

%A _Vladimir Joseph Stephan Orlovsky_, Apr 28 2008

%E More terms from _Colin Barker_, Nov 05 2012

%E Offset corrected by _Tanya Khovanova_, Jul 05 2021