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%I #8 Aug 08 2015 09:07:04
%S 1,2,6,10,17,24,34,44,57,70,86,102,121,140,162,184,209,234,262,290,
%T 321,352,386,420,457,494,534,574,617,660,706,752,801,850,902,954,1009,
%U 1064,1122,1180
%N Row sums of triangle in A204028.
%H <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (2,0,-2,1).
%F G.f.: (1+2*x^2)/((1+x)*(1-x)^3)).
%F a(2*n) = A056109(n).
%F a(2*n+1) = A049450(n+1) = 2*A000326(n+1).
%F a(n) = 2*a(n-1) - 2*a(n-3) + a(n-4), a(0) = 1, a(1) = 2, a(2) = 6, a(3) = 10.
%e Triangle in A204028 begins:
%e 1;............................sum = 1
%e 1, 1;.........................sum = 2
%e 1, 4, 1;......................sum = 6
%e 1, 4, 4, 1;...................sum = 10
%e 1, 4, 7, 4, 1;................sum = 17
%e 1, 4, 7, 7, 4, 1;.............sum = 24
%e 1, 4, 7, 10, 7, 4, 1;.........sum = 34
%e 1, 4, 7, 10, 10, 7, 4, 1;.....sum = 44
%Y Cf. A056109, A049450, A204028.
%K easy,nonn
%O 0,2
%A _Philippe Deléham_, Feb 25 2014
%E Corrected by _R. J. Mathar_, Aug 08 2015
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