Search: id:A077957 Results 1-1 of 1 results found. %I A077957 %S A077957 1,0,2,0,4,0,8,0,16,0,32,0,64,0,128,0,256,0,512,0,1024,0,2048,0,4096,0, %T A077957 8192,0,16384,0,32768,0,65536,0,131072,0,262144,0,524288,0,1048576,0,2097152, %U A077957 0,4194304,0,8388608,0,16777216,0,33554432,0,67108864,0,134217728,0,268435456 %N A077957 Powers of 2 alternating with zeros. %C A077957 Normally sequences like this are not included, since with the alternating 0's deleted it is already in the database. %C A077957 Inverse binomial transform of A001333. - Paul Barry (pbarry(AT)wit.ie), Feb 25 2003 %C A077957 "Sloping binary representation" of powers of 2 (A000079), slope=-1 (see A037095 and A102370) . - Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Jan 04 2008 %C A077957 0,1,0,2,0,4,0,8,0,16,...is the inverse binomial transform of A000129 (Pell numbers). [From Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Oct 28 2008] %F A077957 G.f.: 1/(1-2x^2). E.g.f.: cosh(x sqrt(2)). %F A077957 a(n) = (1 - n mod 2) * 2^floor(n/2). %F A077957 a(n)=sqrt(2)^n*(1+(-1)^n)/2 - Paul Barry (pbarry(AT)wit.ie), May 13 2003 %o A077957 (PARI) a(n)=if(n<0|n%2,0,2^(n/2)) %Y A077957 Cf. A000079, A077966. %Y A077957 Sequence in context: A144775 A046666 A131575 this_sequence A077966 A021102 A021053 %Y A077957 Adjacent sequences: A077954 A077955 A077956 this_sequence A077958 A077959 A077960 %K A077957 nonn %O A077957 0,3 %A A077957 N. J. A. Sloane (njas(AT)research.att.com), Nov 17 2002 Search completed in 0.002 seconds