%I #10 Aug 10 2015 07:32:31

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

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

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

%N First differences of A261093; characteristic function for A219640.

%C a(n) = number of ways to express n as a sum of nonzero terms of A000071 in such a way that no term is used twice, and no two consecutive terms are used at the same time. For 0 we have one solution, an empty sum, thus a(0) = 1.

%H Antti Karttunen, <a href="/A261092/b261092.txt">Table of n, a(n) for n = 0..6765</a>

%F a(0) = 1; a(n) = A261093(n) - A261093(n-1).

%o (Scheme) (define (A261092 n) (if (zero? n) 1 (- (A261093 n) (A261093 (- n 1)))))

%Y Cf. A219640, A261093, A261094, A261095.

%Y Cf. also A079559, A230412 (analogous sequences for other bases), A000071.

%K nonn

%O 0

%A _Antti Karttunen_, Aug 08 2015