%I A006603 M1771
%S A006603 1,2,7,26,107,468,2141,10124,49101,242934,1221427,6222838,32056215,
%T A006603 166690696,873798681,4612654808,24499322137,130830894666,702037771647,
%U A006603 3783431872018,20469182526595,111133368084892,605312629105205
%N A006603 Generalized Fibonacci numbers.
%D A006603 D. G. Rogers, A Schroeder triangle: three combinatorial problems, in 
               "Combinatorial Mathematics V (Melbourne 1976)", Lect. Notes Math. 
               622 (1976), pp. 175-196.
%D A006603 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, 
               Academic Press, 1995 (includes this sequence).
%F A006603 G.f.: [1-x-2x^2-sqrt(1-6x+x^2)]/[2x(1-x+x^2+x^3)]
%Y A006603 a(n) = abs(A080244(n-1)).
%Y A006603 Sequence in context: A000151 A150568 A102319 this_sequence A080244 A124542 
               A003447
%Y A006603 Adjacent sequences: A006600 A006601 A006602 this_sequence A006604 A006605 
               A006606
%K A006603 nonn,easy
%O A006603 0,2
%A A006603 N. J. A. Sloane (njas(AT)research.att.com), Simon Plouffe (simon.plouffe(AT)gmail.com)
%E A006603 More terms from Emeric Deutsch (deutsch(AT)duke.poly.edu), Feb 28 2004