%I #10 May 24 2021 07:37:49
%S 6,102,1008,7860,53340,330372,1918224,10615176,56602260,293032740,
%T 1481004096,7337198232,35743534008,171641101800,814046047200,
%U 3819148459920,17747499595140,81776562767460,373968175442400,1698587342436600,7667851012141320,34422129328312440
%N a(n) = [x^n] 6*(8*x^3 + 3*x + 1) / (1 - 4*x)^(7/2).
%C The sequence and its sister sequence A344401 are related to Frédéric Chapoton's sequences A344228 and A344321, as described in the linked remark.
%H Peter Luschny, <a href="/A344400/a344400.pdf">Remark regarding A344228 and A344321</a>.
%F a(n) = A344228(n+1)*(n+1)*(n+2). - _John Keith_, May 23 2021
%p aList := proc(len) local gf, ser;
%p gf := 6*(8*x^3 + 3*x + 1) / (1 - 4*x)^(7/2):
%p ser := series(gf, x, len+2): seq(coeff(ser, x, n), n = 0..len) end:
%p aList(21);
%Y Cf. A344401, A344228, A344321.
%K nonn
%O 0,1
%A _Peter Luschny_, May 16 2021
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