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a(n+1) = Sum_{k=0..floor(3*n/4)} a(k) * a(n-k).
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%I #15 Oct 15 2021 07:31:07

%S 1,1,1,2,4,9,17,38,89,213,480,1151,2810,6978,16497,40731,101680,

%T 256491,623916,1568966,3972773,10130647,25044032,63573638,162478685,

%U 417322917,1049096179,2687278965,6917001254,17882746627,45391766669,116995255065,302689722551

%N a(n+1) = Sum_{k=0..floor(3*n/4)} a(k) * a(n-k).

%H Seiichi Manyama, <a href="/A030035/b030035.txt">Table of n, a(n) for n = 0..1000</a>

%o (PARI) lista(nn) = {my(v=vector(nn+2, i, 1)); for(n=1, nn, v[n+2]=sum(k=1, 1+(3*n)\4, v[k]*v[n+2-k])); v; } \\ _Jinyuan Wang_, Mar 18 2020

%Y Cf. A000992, A030034, A030038.

%K nonn

%O 0,4

%A _N. J. A. Sloane_

%E More terms from _Jinyuan Wang_, Mar 18 2020