# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a208131 Showing 1-1 of 1 %I A208131 #22 Feb 13 2023 02:57:05 %S A208131 1,3,6,12,36,72,144,432,864,1728,5184,10368,20736,62208,124416,248832, %T A208131 746496,1492992,2985984,8957952,17915904,35831808,107495424,214990848, %U A208131 429981696,1289945088,2579890176,5159780352,15479341056,30958682112,61917364224,185752092672 %N A208131 Partial products of A052901. %H A208131 Reinhard Zumkeller, Table of n, a(n) for n = 0..1000 %H A208131 Index entries for linear recurrences with constant coefficients, signature (0,0,12). %F A208131 a(n+1) = a(n) * A052901(n). %F A208131 A001222(a(n)) = n. %F A208131 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 A208131 Sum_{n>=0} 1/a(n) = 18/11. - _Amiram Eldar_, Feb 13 2023 %t A208131 FoldList[Times,1,PadRight[{},30,{3,2,2}]] (* _Harvey P. Dale_, Mar 19 2013 *) %o A208131 (Haskell) %o A208131 a208131 n = a208131_list !! n %o A208131 a208131_list = scanl (*) 1 $ a052901_list %o A208131 -- _Reinhard Zumkeller_, Mar 29 2012 %Y A208131 Cf. A001222, A052901, A026549, A026532. %K A208131 nonn %O A208131 0,2 %A A208131 _Reinhard Zumkeller_, Apr 04 2012 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE