A127988 Sequence determining the parity of A025748.

0, 8, 32, 40, 128, 136, 160, 168, 512, 520, 544, 552, 640, 648, 672, 680, 2048, 2056, 2080, 2088, 2176, 2184, 2208, 2216, 2560, 2568, 2592, 2600, 2688, 2696, 2720, 2728, 8192, 8200, 8224, 8232, 8320, 8328, 8352, 8360, 8704, 8712, 8736

Offset

0,2

Comments

Odd terms occur in A025748 at positions (0),1,2,3,(8),9,10,11,(32),33,34,35,(40),...

Links

Table of n, a(n) for n=0..42.

Formula

a(n)=8*A000695(n); a(n)=4*sum{k=0..floor(log_2(n+1)), mod(floor(n/2^k),2)2^(2k+1)};

Crossrefs

Sequence in context: A059880 A144096 A371444 * A371454 A129749 A005879

Adjacent sequences: A127985 A127986 A127987 * A127989 A127990 A127991

Keyword

easy,nonn

Author

Paul Barry, Feb 09 2007

Status

approved