%I #19 Feb 28 2024 11:32:37
%S 0,1,84,2925,85320,2362041,64304604,1741001445,47050068240,
%T 1270739210481,34313445309924,926494403955165,25015631334908760,
%U 675424587904113321,18236486750190760044,492385348146244352085,13294406252968671566880
%N a(n) = 3^n*(3^n-1)*(3^n-2)/6.
%H G. C. Greubel, <a href="/A026809/b026809.txt">Table of n, a(n) for n = 0..690</a>
%H <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (39, -351, 729).
%F a(n) = binomial(3^n, 3), n >= 0. - _Zerinvary Lajos_, Jan 07 2008
%p seq(binomial(3^n,3),n=0..16); # _Zerinvary Lajos_, Jan 07 2008
%t Binomial[3^Range[0, 20], 3] (* _G. C. Greubel_, Nov 08 2019 *)
%o (PARI) vector(21, n, binomial(3^(n-1), 3) ) \\ _G. C. Greubel_, Nov 08 2019
%o (Magma) [Binomial(3^n, 3): n in [0..20]]; // _G. C. Greubel_, Nov 08 2019
%o (Sage) [binomial(3^n, 3) for n in (0..20)] # _G. C. Greubel_, Nov 08 2019
%o (GAP) List([0..20], n-> Binomial(3^n, 3) ); # _G. C. Greubel_, Nov 08 2019
%Y Subsequence of A000292.
%K nonn
%O 0,3
%A _N. J. A. Sloane_