%I #27 Mar 11 2024 08:08:51
%S 0,1,20,220,1540,7770,30856,102340,295240,762355,1798940,3939936,
%T 8104460,15803060,29426320,52636760,90889616,152112005,247574180,
%U 392991060,609896980,927341646,1383960600,2030479100,2932714200,4175145975,5865135276,8137872120
%N a(n) = A000292(A000292(n)).
%H N. J. A. Sloane, <a href="/A140236/b140236.txt">Table of n, a(n) for n = 0..10000</a>
%H <a href="/index/Rec#order_10">Index entries for linear recurrences with constant coefficients</a>, signature (10,-45,120,-210,252,-210,120,-45,10,-1).
%F a(n) = (n*(1 + n)*(2 + n)*(3 + n)*(2 + n^2)*(12 + n*(1 + n)*(2 + n)))/1296.
%F G.f.: x*(1+10*x+65*x^2+120*x^3+80*x^4+4*x^5)/(1-x)^10. - _Colin Barker_, Apr 30 2012.
%p a:= (n-> binomial(n+2,3))@@2:
%p seq(a(n), n=0..29); # _Alois P. Heinz_, Mar 11 2024
%t Table[(n (1 + n) (2 + n) (3 + n) (2 + n^2) (12 + n (1 + n) (2 + n)))/1296,{n,0,20}]
%o (PARI) b(n)=n*(n+1)*(n+2)/6;
%o a(n)=b(b(n));
%o vector(25,n,a(n-1)) \\ _Joerg Arndt_, Mar 11 2024
%Y Row n=3 of A331436.
%Y Cf. A000292.
%K nonn,easy
%O 0,3
%A _Artur Jasinski_, May 14 2008
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