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Number of separable partitions of n in which the number of distinct (repeatable) parts <= 4.
1

%I #4 May 16 2019 21:18:43

%S 1,1,2,3,5,6,10,14,19,26,37,49,66,87,115,150,193,244,309,387,479,585,

%T 714,860,1032,1226,1454,1697,1991,2304,2672,3060,3518,3981,4541,5121,

%U 5782,6462,7265,8057,9000,9938,11031,12131,13384,14634,16085,17534,19161

%N Number of separable partitions of n in which the number of distinct (repeatable) parts <= 4.

%C A partition is separable if there is an ordering of its parts in which no consecutive parts are identical. See A325534 for a guide to related sequences.

%t (separable=Table[Map[#[[1]]&,Select[Map[{#,Quotient[(1+Length[#]),Max[Map[Length,Split[#]]]]}&,IntegerPartitions[nn]],#[[2]]>1&]],{nn,35}]);

%t Map[Length[Select[Map[{#,Length[Union[#]]}&,#],#[[2]]<=4&]]&,separable]

%t (* _Peter J. C. Moses_, May 08 2019 *)

%Y Cf. A000041, A325334.

%K nonn,easy

%O 1,3

%A _Clark Kimberling_, May 16 2019