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%I #17 Nov 15 2014 06:56:26
%S 1,2,4,7,15,27,58,106,227,419,894,1662,3534,6606,14004,26292,55587,
%T 104739,220918,417526,878810,1665242,3498444,6644172,13934990,
%U 26517902,55531948,105863596,221384892,422711484,882865128,1688171496,3521765667,6742991139
%N a(n) = A027306(n) + A027306(n-1) for n > 0; a(0) = 1.
%C Central terms of triangle in A249111.
%H Reinhard Zumkeller, <a href="/A248574/b248574.txt">Table of n, a(n) for n = 0..1000</a>
%o (Haskell)
%o a248574 0 = 1
%o a248574 n = a027306 (n - 1) + a027306 n
%Y Cf. A027306, A249111.
%K nonn
%O 0,2
%A _Reinhard Zumkeller_, Nov 14 2014