1,4

http://mathworld.wolfram.com/notebooks/Combinatorics/GrayCode.nb.

Table of n, a(n) for n=1..91.

a(n)=GrayCode[Hofstadter[n] - 1, 4].

<< DiscreteMath`CombinatorialFunctions` (* rather than put in the whole code :needs GrayCode.nb *) Table[GrayCode[Hofstadter[n] - 1, 4], {n, 100}]

Sequence in context: A110898 A264756 A267942 * A106365 A200174 A266153

Adjacent sequences: A147991 A147992 A147993 * A147995 A147996 A147997

nonn

Roger L. Bagula and Gary W. Adamson, Nov 18 2008

approved