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A272038 Somos's sequence {b(9,n)} defined in comment in A078495: a(0)=a(1)=...=a(20)=1; for n>=21, a(n)=(a(n-1)*a(n-20)+a(n-10)*a(n-11))/a(n-21).

%I A272038 #25 May 04 2016 08:50:51
%S A272038 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,3,4,5,6,7,8,9,10,11,13,
%T A272038 19,31,51,81,123,179,251,341,451,1045,1691,2451,3459,4977,7467,11679,
%U A272038 18755,30349,48763,100474,282777,679512,1391391,2547414,4327101
%N A272038 Somos's sequence {b(9,n)} defined in comment in A078495: a(0)=a(1)=...=a(20)=1; for n>=21, a(n)=(a(n-1)*a(n-20)+a(n-10)*a(n-11))/a(n-21).
%H A272038 Seiichi Manyama, <a href="/A272038/b272038.txt">Table of n, a(n) for n = 0..578</a>
%o A272038 (Ruby)
%o A272038 def b(k, n)
%o A272038   b = Array.new(2 * k + 3, 1)
%o A272038   (2 * k + 3..n).each{|i|
%o A272038     j = (b[i - 1] * b[i - 2 * k - 2] + b[i - k - 1] * b[i - k - 2]) / b[i - 2 * k - 3].to_r
%o A272038     j = j.to_i if j.denominator == 1
%o A272038     b[i] = j
%o A272038   }
%o A272038   b[0..n]
%o A272038 end
%o A272038 p b(9, n) # _Seiichi Manyama_, May 04 2016
%Y A272038 Cf. A006721, A078495, A268199, A271954, A271948, A271949, A271950, A271952, A271955.
%K A272038 nonn
%O A272038 0,22
%A A272038 _Vladimir Shevelev_ and _Peter J. C. Moses_, Apr 18 2016