%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