%I A055988
%S A055988 1,2,7,26,95,345,1252,4544,16493,59864,217286,788674,2862617,10390321,
%T A055988 37713313,136886433,496850954,1803399103,6545722210,23758733815,
%U A055988 86236081273,313007493212,1136110191472,4123691589365,14967590689568
%N A055988 Sequence is its own 4th difference.
%C A055988 Row sums of Riordan array (1/(1-x), x/(1-x)^4), A109960. - Paul Barry 
               (pbarry(AT)wit.ie), Jul 06 2005
%F A055988 a(n)=5a(n-1)-6a(n-2)+4a(n-3)-a(n-4) =a(n-1)+A055991(n-1) =A055989(n)-A055989(n-1) 
               =A055990(n)-2*A055990(n-1)+A055990(n-2)
%F A055988 G.f.: (1-x)^3/(1-5x+6x^2-4x^3+x^4); a(n)=sum{k=0..n, binomial(n+3k, 4k)}. 
               - Paul Barry (pbarry(AT)wit.ie), Jul 06 2005
%Y A055988 Cf. A055989, A055990, A055991 for the other differences of a(n). See 
               A000079, A001906, A052529 for examples of sequences which are respectively 
               their own first, second and third differences.
%Y A055988 Sequence in context: A134063 A087448 A129273 this_sequence A001075 A113436 
               A126223
%Y A055988 Adjacent sequences: A055985 A055986 A055987 this_sequence A055989 A055990 
               A055991
%K A055988 nonn
%O A055988 1,2
%A A055988 Henry Bottomley (se16(AT)btinternet.com), Jun 02 2000
%E A055988 More terms from James A. Sellers (sellersj(AT)math.psu.edu), Jun 05 2000