|
%I #18 Sep 08 2022 08:45:06
%S 2,30,480,7392,110880,1633632,23761920,342328320,4895294976,
%T 69589977600,984515051520,13872712089600,194821130649600,
%U 2728095278727168,38106727702855680,531128942672216064
%N a(n) = 2^n*binomial(3*n,n)*(3*n+2).
%H Vincenzo Librandi, <a href="/A072976/b072976.txt">Table of n, a(n) for n = 0..100</a>
%F Sum_{k>=0} 1/a(k) = (7*Pi - 24*log(2))/10 = 0.53556162416898...
%t Table[2^n Binomial[3n,n](3n+2),{n,0,20}] (* _Harvey P. Dale_, Aug 20 2011 *)
%o (PARI) a(n)=2^n*binomial(3*n,n)*(3*n+2)
%o (Magma) [2^n*Binomial(3*n,n)*(3*n+2): n in [0..20]]; // _Vincenzo Librandi_, Aug 20 2011
%K easy,nonn
%O 0,1
%A _Benoit Cloitre_, Aug 13 2002
%E a(1) corrected by _Harvey P. Dale_, Aug 20 2011
|
