Search: id:A122803 Results 1-1 of 1 results found. %I A122803 %S A122803 1,2,4,8,16,32,64,128,256,512,1024,2048,4096,8192,16384,32768,65536,131072, %T A122803 262144,524288,1048576,2097152,4194304,8388608,16777216,33554432,67108864, %U A122803 134217728,268435456,536870912,1073741824,2147483648,4294967296 %V A122803 1,-2,4,-8,16,-32,64,-128,256,-512,1024,-2048,4096,-8192,16384,-32768, 65536,-131072, %W A122803 262144,-524288,1048576,-2097152,4194304,-8388608,16777216,-33554432,67108864, %X A122803 -134217728,268435456,-536870912,1073741824,-2147483648,4294967296 %N A122803 Powers of -2. %C A122803 Sum_{n>=0} 1/a(n) = 2/3 [From Jaume Oliver Lafont (joliverlafont(AT)gmail.com), Mar 01 2009] %H A122803 Franklin T. Adams-Watters, Table of n, (-2)^n for n = 0..1000 %H A122803 Index entries for sequences related to linear recurrences with constant coefficients %H A122803 Tanya Khovanova, Recursive Sequences %F A122803 a(n) = (-2)^n. %F A122803 a(n) = - 4a(n-1) - 4a(n-2). - Tanya Khovanova (tanyakh(AT)yahoo.com), Feb 01 2007 %F A122803 a(n)=-2*a(n-1), n>0 ; a(0)=1 . G.f.: 1/(1+2x). [From Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Nov 19 2008] %p A122803 a:=n->mul(-2, k=0..n): seq(a(n), n=-1..31); - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Jan 22 2008 %Y A122803 Cf. A000079 (powers of 2). %Y A122803 Sequence in context: A141531 A166444 A084633 this_sequence A000079 A120617 A050732 %Y A122803 Adjacent sequences: A122800 A122801 A122802 this_sequence A122804 A122805 A122806 %K A122803 easy,sign %O A122803 0,2 %A A122803 Franklin T. Adams-Watters (FrankTAW(AT)Netscape.net), Sep 11 2006 Search completed in 0.001 seconds