%I A131601
%S A131601 49,97,145,2497,7153,14113,133969,477313,1154737,7585249,30496273
%N A131601 The number of different configurations of an n-block of a shift space 
               with k symbols where each symbol but the first must appear isolated 
               and separated from others by an block of length at least m made of 
               first symbol For k=2 is the number of different configurations of 
               an n-bits string where each 1 is isolated and separated by at least 
               m zeros.
%C A131601 a(n+1)/a(n) -> 4.
%D A131601 math:archiv:0708.4370
%H A131601 R. Tonelli, <a href="http://www.arXiv.org/list/math.ST/recent">Fibonacci-like 
               sequences and shift spaces</a>.
%F A131601 a(n) = a(n-1) + (k-1)*a(n-m-1), where k=49, m=2
%F A131601 G.f.: -x*(49+48*x+48*x^2)/(4*x-1)/(12*x^2+3*x+1). - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), 
               Nov 14 2007
%Y A131601 Cf. A000045, A000930.
%Y A131601 Sequence in context: A043250 A044030 A165339 this_sequence A044138 A043394 
               A044519
%Y A131601 Adjacent sequences: A131598 A131599 A131600 this_sequence A131602 A131603 
               A131604
%K A131601 easy,nonn
%O A131601 1,1
%A A131601 R. Tonelli (roberto.tonelli(AT)dsf.unica.it), Aug 31 2007