A109899 - OEIS

%I #7 Aug 08 2015 22:28:48

%S 3,2,105,12,27027,160,18706545,15,1616615,96768,55382044433625,336,

%T 182057820682381875,158146560,260015,495,5087360695596105163111875,

%U 12812800,39805919884778682846001415625,576576,767633625

%N a(n) = least integer of the form (n+2)(n+4)...(n+2k)/n, or 0 if no such number exists.

%e a(3) = 5*7*9/3 = 105.

%p A109899 := proc(n) local k; k := 1; while mul(n+2*i,i=1..k) mod n <> 0 do k := k+1; od ; RETURN(mul(n+2*i,i=1..k)/n) ; end: seq(A109899(n),n=1..30) ; # _R. J. Mathar_, Aug 15 2007

%Y Cf. A109898.

%K nonn

%O 1,1

%A _Amarnath Murthy_, Jul 13 2005

%E More terms from _R. J. Mathar_, Aug 15 2007