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A085524 a(0) = 0; a(n) = n^(2*n-1) for n > 0. 6

%I #59 Nov 02 2022 07:43:29

%S 0,1,8,243,16384,1953125,362797056,96889010407,35184372088832,

%T 16677181699666569,10000000000000000000,7400249944258160101211,

%U 6624737266949237011120128,7056410014866816666030739693,8819763977946281130444984418304,12783403948858939111232757568359375

%N a(0) = 0; a(n) = n^(2*n-1) for n > 0.

%C For n > 0, a(n) is the square of the determinant of the (2*n) X (2*n) matrix with elements M(j,k) = cos(Pi*j*k/n). See the MathOverflow link. - _Hugo Pfoertner_, Sep 18 2021

%H Joerg Arndt, <a href="/A085524/b085524.txt">Table of n, a(n) for n = 0..100</a>

%H Zhi-Wei Sun, Fedor Petrov, <a href="https://mathoverflow.net/questions/321098/">A surprising identity</a>, discussion in MathOverflow, Jan 17 2019.

%F a(n) = n! * [x^n] -LambertW(-n*x). - _Ilya Gutkovskiy_, Oct 04 2017

%F a(n) = A089072(2*n-1, n), n >= 1. - _G. C. Greubel_, Nov 01 2022

%t Join[{0}, Table[n^(2 n - 1), {n, 20}]] (* _Harvey P. Dale_, May 16 2016 *)

%o (PARI) a(n) = if(n==0, 0, n^(2*n-1)) \\ _Altug Alkan_, Oct 04 2017

%o (Magma) [n eq 0 select 0 else n^(2*n-1): n in [0..30]]; // _G. C. Greubel_, Nov 01 2022

%o (SageMath) [0]+[n^(2*n-1) for n in range(1,31)] # _G. C. Greubel_, Nov 01 2022

%Y Cf. A062206, A085526, A089072.

%K nonn

%O 0,3

%A _N. J. A. Sloane_, Jul 05 2003

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Last modified March 28 08:22 EDT 2024. Contains 371236 sequences. (Running on oeis4.)