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Triangle read by rows in which row n lists the parts of the largest subshell of all partitions of 2n that do not contain 1 as a part.
1

%I #9 Nov 30 2013 21:30:32

%S 2,4,2,6,3,3,2,2,8,4,4,5,3,2,2,2,2,10,5,5,6,4,7,3,4,3,3,2,2,2,2,2,2,2,

%T 12,6,6,7,5,8,4,4,4,4,9,3,5,4,3,6,3,3,3,3,3,3,2,2,2,2,2,2,2,2,2,2,2,2,

%U 14,7,7,8,6,9,5

%N Triangle read by rows in which row n lists the parts of the largest subshell of all partitions of 2n that do not contain 1 as a part.

%C In the shell model of partitions the head of the last section of the set of partitions of 2n contains n subshells. The first n rows of this triangle represent these subsells.

%C This sequence contains the same elements of A182742 but in distinct order.

%C See A135010 and A138121 for more information.

%e For n=1 the unique partition of 2n that does not contains 1 as part is 2, so row 1 has an element = 2.

%e For n=2 there are 2 partitions of 2n that do not contain 1 as part:

%e 4 ............ or ....... 4 . . .

%e 2 + 2 ........ or .......(2). 2 .

%e These partitions contain (2), the row n-1 of triangle, so

%e the parts of the largest subshell are 4, 2.

%e For n=3 there are 4 partitions of 2n that do not contain 1 as part:

%e 6 ............ or ....... 6 . . . . .

%e 3 + 3 ........ or ....... 3 . . 3 . .

%e 4 + 2 ........ or .......(4). . . 2 .

%e 2 + 2 + 2 .... or .......(2).(2). 2 .

%e These partitions contain (4) and (2),(2), the parts of rows < n of triangle, so the parts of the largest subshell are 6, 3, 3, 2, 2.

%e And so on.

%e Triangle begins:

%e 2,

%e 4, 2,

%e 6, 3, 3, 2, 2,

%e 8, 4, 4, 5, 3, 2, 2, 2, 2,

%e 10, 5, 5, 6, 4, 7, 3, 4, 3, 3, 2, 2, 2, 2, 2, 2, 2,

%Y Cf. A135010, A138121, A182734, A182736, A182742, A182746, A182813.

%K nonn,tabf

%O 1,1

%A _Omar E. Pol_, Dec 04 2010