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%I #8 Feb 24 2018 11:54:36
%S 1,2,4,6,9,12,17,22,30,38,51,64,85,106,140,174,229,284,373,462,606,
%T 750,983,1216,1593,1970,2580,3190,4177,5164,6761,8358,10942,13526,
%U 17707,21888,28653,35418,46364,57310,75021,92732,121389,150046,196414,242782
%N Row sums of triangle in A204026.
%H <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (1,1,-1,1,-1).
%F G.f.: (1+x)*(1+x^2)/((1-x^2-x^4)*(1-x)).
%F a(n) = a(n-1) + a(n-2) - a(n-3) + a(n-4) - a(n-5), a(0) = 1, a(1) = 2, a(2) = 4, a(3) = 6, a(4) = 9.
%F a(2*n) = A157728(n+5) = A000045(n+5) - 4.
%F a(2*n+1) = 2*A001911(n+1) = 2*A000045(n+4) - 4.
%e Triangle in A204026 begins:
%e 1;.........................sum = 1
%e 1, 1;......................sum = 2
%e 1, 2, 1;...................sum = 4
%e 1, 2, 2, 1;................sum = 6
%e 1, 2, 3, 2, 1;.............sum = 9
%e 1, 2, 3, 3, 2, 1;..........sum = 12
%e 1, 2, 3, 5, 3, 2, 1;.......sum = 17
%e 1, 2, 3, 5, 5, 3, 2, 1;....sum = 22
%e 1, 2, 3, 5, 8, 5, 3, 2, 1;.sum = 30
%t LinearRecurrence[{1,1,-1,1,-1},{1,2,4,6,9},50] (* _Harvey P. Dale_, Feb 24 2018 *)
%Y Cf. A000045, A001911, A157728, A204026
%K easy,nonn
%O 0,2
%A _Philippe Deléham_, Feb 25 2014
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