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Row sums of A321623.
1

%I #14 Feb 05 2020 05:34:14

%S 1,4,20,108,604,3444,19876,115644,676748,3977316,23451700,138634764,

%T 821221692,4872734676,28952250564,172222729308,1025461169772,

%U 6110912705220,36441840179284,217450403367852,1298228971572764,7754336590794804,46335720234364900

%N Row sums of A321623.

%F G.f.: 1/(sqrt(1 - 6*x + x^2) - x). - _Philippe Deléham_, Feb 05 2020

%t (* The function RiordanSquare is defined in A321620. *)

%t LargeSchröder = (1 - x - Sqrt[1 - 6x + x^2])/(2x);

%t M = RiordanSquare[LargeSchröder, 23]; Map[Total, M]

%t (* Alternative: *)

%t CoefficientList[Series[1/(Sqrt[1-6x+x^2]-x),{x,0,22}],x] (* _Stefano Spezia_, Feb 05 2020 *)

%Y Cf. A321623, A321620.

%K nonn

%O 0,2

%A _Peter Luschny_, Nov 22 2018