cp's OEIS Frontend

A048142 Number of symmetrical planar partitions of n: planar partitions (A000219) that when regarded as 3-D objects have only a threefold axis of symmetry, i.e., C3 symmetry.

%I A048142 #27 May 23 2025 15:12:02
%S A048142 0,0,0,0,0,0,0,0,0,0,0,0,1,1,0,1,1,0,2,2,0,3,3,0,5,6,0,7,9,0,11,16,1,
%T A048142 14,23,2,20,36,4,27,52,7,37,78,13,48,111,21,65,163,36,83,227,56,109,
%U A048142 322,89,139,444,135,179,618,207,226,841,305,288,1151,453,361
%N A048142 Number of symmetrical planar partitions of n: planar partitions (A000219) that when regarded as 3-D objects have only a threefold axis of symmetry, i.e., C3 symmetry.
%C A048142 Only one of the pair left-handed, right-handed, is enumerated.
%H A048142 Wouter Meeussen, <a href="/A048142/b048142.txt">Table of n, a(n) for n = 1..202</a>
%F A048142 a(n) = (A096419(n) - A048141(n))/2.
%e A048142 The plane partitions {{3, 2, 2}, {3, 1}, {1, 1}} and {{3, 2, 2}, {3, 2}, {1, 1}} have C3 symmetry.
%Y A048142 Cf. A000219, A000784, A000785, A000786, A005987, A048141, A051056-A051061, A096419.
%K A048142 nice,nonn
%O A048142 1,19
%A A048142 _Wouter Meeussen_