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Characteristic function of numbers that can be written as p+2^k, where p is prime and p less than 2^k (A118957).
4

%I #6 Mar 30 2012 18:50:54

%S 0,0,0,0,0,1,1,0,0,1,1,0,1,0,1,0,0,1,1,0,1,0,1,0,0,0,1,0,1,0,0,0,0,1,

%T 1,0,1,0,1,0,0,0,1,0,1,0,0,0,1,0,1,0,0,0,1,0,0,0,0,0,1,0,1,0,0,1,1,0,

%U 1,0,1,0,0,0,1,0,1,0,0,0,1,0,1,0,0,0,1,0,0,0,0,0,1,0,1,0,0,0,0,0,1,0,0,0,1

%N Characteristic function of numbers that can be written as p+2^k, where p is prime and p less than 2^k (A118957).

%C 0 <= a(n) <= 1, a(n) <= A109925(n);

%C a(A118956(n)) = 0, a(A118957(n)) = 1;

%C A118953(n) = a(A000040(n)).

%H <a href="/index/Ch#char_fns">Index entries for characteristic functions</a>

%K nonn

%O 1,1

%A _Reinhard Zumkeller_, May 07 2006