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%I #8 Apr 13 2017 16:05:42
%S 1,2,6,14,33,64,127,228,404,672,1100,1724,2661,3974,5849,8402,11911,
%T 16556,22751,30772,41198,54436,71283,92316,118609,150950,190753,
%U 239090,297783,368236,452782,553240,672532,812980,978211,1171144,1396235
%N Number of planar partitions of n with trace 4.
%C Also number of partitions of n objects of 2 colors into 4 parts, each part containing at least one black object.
%D G. E. Andrews, The Theory of Partitions, Addison-Wesley, 1976 (Ch. XI, exercise 5 and Ch. XII, exercise 5).
%F G.f.: q^4*(q^12+q^10+2*q^9+4*q^8+2*q^7+4*q^6+2*q^5+4*q^4+2*q^3+q^2+1) / ((-1+q^4)^2*(-1+q^3)^2*(-1+q^2)^2*(-1+q)^2).
%Y Column 4 of A089353. Cf. A000219, A005380, A005993 (trace 2), A050531 (trace 3).
%K easy,nonn
%O 4,2
%A _Wouter Meeussen_ and _Vladeta Jovovic_, Dec 26 2003
%E Edited and extended by _Christian G. Bower_, Jan 08 2004
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