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a(n)=A033005(n)/8.
1

%I #6 Feb 03 2014 12:46:14

%S 1,2,3,4,5,6,49,51,52,53,54,55,98,99,101,102,103,104,147,148,149,151,

%T 152,153,196,197,198,199,201,202,245,246,247,248,249,251,294,295,296,

%U 297,298,299,2402,2403,2404,2405,2406,2407,2499

%N a(n)=A033005(n)/8.

%C Numbers which, written in base 49, have only digits 0 through 6 and no two adjacent digits equal. - _M. F. Hasler_, Feb 03 2014

%o (PARI) is_A043311(n)=(n=[n])&&!until(!n[1],((n=divrem(n[1],49))[2]<7 && n[1]%7!=n[2])||return) \\ _M. F. Hasler_, Feb 03 2014

%Y Cf. A043307 - A043320, A043291, A033001 - A033014, A033016 - A033029. ~

%K nonn,base

%O 1,2

%A _Clark Kimberling_