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%I #11 Aug 20 2024 14:14:12
%S 0,0,0,1,3,9,43,209,1042,5682,32875,200919,1299092,8848623,63108778,
%T 471509591,3671980053,29797471739,251120234182,2196428139810,
%U 19882638695048,186205573812059,1799766634300161,17946783669353462,184277407872729741,1947501874827169041
%N Number of set partitions of [n] having at least two blocks with equal element sums.
%F a(n) = A000110(n) - A275780(n).
%e a(3) = 1: 12|3
%e a(4) = 3: 12|3|4, 13|2|4, 14|23.
%e a(5) = 9: 12|3|45, 12|3|4|5, 13|25|4, 13|2|4|5, 14|23|5, 1|23|4|5, 14|2|3|5, 15|24|3, 1|25|34.
%Y Cf. A000110, A035470, A275780.
%K nonn
%O 0,5
%A _Alois P. Heinz_, Aug 08 2016
%E a(17)-a(25) from _Christian Sievers_, Aug 20 2024