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Number of set partitions of [n] into subsets whose element sums are distinct squares.
6

%I #13 Feb 04 2017 18:50:06

%S 1,1,0,0,1,0,1,0,1,23,9,41,248,277,1556,2854,5233,20701,145137,

%T 1626890,4118910,9963276,9260756,64027363,365237571,1002679107,

%U 21594036300,24465529531,144914973347,1921444799766

%N Number of set partitions of [n] into subsets whose element sums are distinct squares.

%e a(0) = 1: {}.

%e a(1) = 1: 1.

%e a(4) = 1: 1|234.

%e a(6) = 1: 1|2356|4.

%e a(8) = 1: 12345678.

%e a(9) = 23: 12345678|9, 123568|4|79, 1236789|45, 1245789|36, 126|345789, 12589|367|4, 1258|3679|4, 12679|358|4, 1267|3589|4, 1345689|27, 135|246789, 13|24568|79, 13579|268|4, 1357|2689|4, 13678|259|4, 13|259|4678, 13|2689|457, 13|268|4579, 156789|234, 18|2345679, 169|23578|4, 1789|2356|4, 178|23569|4.

%e a(10) = 9: 1|2356|4|78(10)|9, 1|23578|4|6(10)|9, 1|258(10)|367|4|9, 1|258(10)|36|4|79, 1|259|36|4|78(10), 1|267(10)|358|4|9, 1|268|357(10)|4|9, 1|27|3589|4|6(10), 1|27|358|4|69(10).

%Y Cf. A252897, A275780, A278329, A278340, A281994.

%K nonn

%O 0,10

%A _Alois P. Heinz_, Nov 18 2016