|
%I #28 Apr 26 2018 08:41:48
%S 1,1,2,4,10,25,70,199,588,1784,5544,17569,56628,185202,613470,2054998,
%T 6952660,23732911,81662152,283026021,987369656,3465222945,12228193432,
%U 43369190282,154532114800,552998717472,1986841476000,7164993393905,25928281261800,94132464529902
%N a(n) = floor(C(n/2)*C(n/2+1)), where C = Catalan numbers (A000108).
%e k a(k) is prime
%e 2 2
%e 7 199
%e 11 17569
%e 17 23732911
%e 81 102313363987695596246576033222404783284068513
%e 619 200823128294216578246...307006792344011246479 (366 digits)
%t Table[Floor[CatalanNumber[n/2] CatalanNumber[n/2 + 1]], {n, 0, 35}]
%Y Cf. A000108, A005568 (bisection, even part), A005817.
%K nonn
%O 0,3
%A _Vincenzo Librandi_, Apr 11 2018
|
