|
%I #22 Feb 13 2023 02:57:05
%S 1,3,6,12,36,72,144,432,864,1728,5184,10368,20736,62208,124416,248832,
%T 746496,1492992,2985984,8957952,17915904,35831808,107495424,214990848,
%U 429981696,1289945088,2579890176,5159780352,15479341056,30958682112,61917364224,185752092672
%N Partial products of A052901.
%H Reinhard Zumkeller, <a href="/A208131/b208131.txt">Table of n, a(n) for n = 0..1000</a>
%H <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,12).
%F a(n+1) = a(n) * A052901(n).
%F A001222(a(n)) = n.
%F a(n) = 12^floor(n/3)*(r+1)*(r+2)/2 with r = n mod 3. G.f.: -(6*x^2+3*x+1) / (12*x^3-1). - _Alois P. Heinz_, Apr 05 2012
%F Sum_{n>=0} 1/a(n) = 18/11. - _Amiram Eldar_, Feb 13 2023
%t FoldList[Times,1,PadRight[{},30,{3,2,2}]] (* _Harvey P. Dale_, Mar 19 2013 *)
%o (Haskell)
%o a208131 n = a208131_list !! n
%o a208131_list = scanl (*) 1 $ a052901_list
%o -- _Reinhard Zumkeller_, Mar 29 2012
%Y Cf. A001222, A052901, A026549, A026532.
%K nonn
%O 0,2
%A _Reinhard Zumkeller_, Apr 04 2012
|
