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%I #11 Feb 24 2021 15:29:20
%S 1,1,4,11,30,81,217,578,1533,4053,10690,28145,74001,194370,510133,
%T 1338077,3508194,9194697,24092281,63114914,165317997,432970149,
%U 1133854594,2969117921,7774547745,20356622466,53299513957,139550308013,365368187298,956587808313,2504462346505
%N a(n) = [x^n] (x - 1)^4/((1 - 2*x)*(x^2 - 3*x + 1)).
%C Row sums of A341103.
%F a(n) = Sum_{k=0..n} Sum_{j=0..k}(binomial(n + k - j, 2*k) - binomial(n + j - 1, 2*k)) for n >= 1.
%F a(n) = 5*a(n-1) - 7*a(n-2) + 2*a(n-3) for n >= 5.
%o (PARI) a(n) = if (n, sum(k=0, n, sum(j=0, k, binomial(n+k-j, 2*k) - binomial(n+j-1, 2*k))), 1); \\ _Michel Marcus_, Feb 24 2021
%Y Cf. A341103.
%K nonn,easy
%O 0,3
%A _Peter Luschny_, Feb 24 2021