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a(n) = binomial(n,6)-1.
3

%I #10 Dec 27 2023 17:55:16

%S 0,6,27,83,209,461,923,1715,3002,5004,8007,12375,18563,27131,38759,

%T 54263,74612,100946,134595,177099,230229,296009,376739,475019,593774,

%U 736280,906191,1107567,1344903,1623159,1947791,2324783,2760680,3262622

%N a(n) = binomial(n,6)-1.

%H <a href="/index/Rec#order_07">Index entries for linear recurrences with constant coefficients</a>, signature (7, -21, 35, -35, 21, -7, 1).

%F a(n) = A000579(n)-1.

%F a(0)=0, a(1)=6, a(2)=27, a(3)=83, a(4)=209, a(5)=461, a(6)=923, a(n)= 7*a(n-1)- 21*a(n-2)+35*a(n-3)-35*a(n-4)+21*a(n-5)-7*a(n-6)+ a(n-7). - _Harvey P. Dale_, Dec 26 2015

%p [seq(binomial(n,6)-1,n=6..42)];

%t Binomial[Range[6,40],6]-1 (* or *) LinearRecurrence[{7,-21,35,-35,21,-7,1},{0,6,27,83,209,461,923},40] (* _Harvey P. Dale_, Dec 26 2015 *)

%o (Magma) [Binomial(n,6)-1 : n in [6..40]]; // _Wesley Ivan Hurt_, Dec 27 2023

%Y Cf. A000096, A000579, A062748, A063258, A062988.

%K easy,nonn

%O 6,2

%A _Zerinvary Lajos_, Nov 25 2006