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A017091 a(n) = (8*n + 2)^3. 1

%I #22 Apr 24 2023 02:54:27

%S 8,1000,5832,17576,39304,74088,125000,195112,287496,405224,551368,

%T 729000,941192,1191016,1481544,1815848,2197000,2628072,3112136,

%U 3652264,4251528,4913000,5639752,6434856,7301384,8242408,9261000,10360232,11543176,12812904,14172488,15625000

%N a(n) = (8*n + 2)^3.

%H Vincenzo Librandi, <a href="/A017091/b017091.txt">Table of n, a(n) for n = 0..10000</a>

%H <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (4,-6,4,-1).

%F G.f.: 8*(1 + 121*x + 235*x^2 + 27*x^3)/(x-1)^4. - _R. J. Mathar_, Jul 14 2016

%F From _Amiram Eldar_, Apr 24 2023: (Start)

%F a(n) = A017089(n)^3.

%F a(n) = 2^3*A016815(n).

%F Sum_{n>=0} 1/a(n) = Pi^3/512 + 7*zeta(3)/128. (End)

%t (8*Range[0,30]+2)^3 (* or *) LinearRecurrence[{4,-6,4,-1},{8,1000,5832,17576},30] (* _Harvey P. Dale_, Dec 30 2019 *)

%o (Magma) [(8*n+2)^3: n in [0..35]]; // _Vincenzo Librandi_, Jul 12 2011

%Y Cf. A002117, A016815, A017089 (8n+2), A000578 (n^3).

%K nonn,easy

%O 0,1

%A _N. J. A. Sloane_

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Last modified April 18 13:29 EDT 2024. Contains 371780 sequences. (Running on oeis4.)