A238793 Number of palindromic partitions of n such that 2*(multiplicity of least part) = (multiplicity of greatest part).
0, 0, 0, 0, 1, 0, 1, 1, 1, 2, 3, 1, 3, 3, 6, 5, 6, 5, 9, 9, 13, 10, 17, 13, 23, 18, 29, 23, 37, 32, 48, 37, 64, 48, 81, 60, 99, 77, 130, 94, 158, 123, 200, 145, 252, 182, 309, 224, 381, 277, 475, 331, 575, 414, 712, 497, 866, 605, 1049, 736, 1274, 883, 1555
Offset: 1
Examples
a(15) counts these 6 partitions (written as palindromes): 717, 636, 25152, 13431, 12233221..
Programs
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Mathematica
z = 65; p[n_] := p[n] = Select[IntegerPartitions[n], (Count[OddQ[Transpose[Tally[#]][[2]]], True] <= 1) && (2*Count[#, Min[#]] == Count[#, Max[#]]) &]; Table[p[n], {n, 1, 16}] t1 = Table[Length[p[n]], {n, 1, z}] (* Peter J. C. Moses, Mar 03 2014 *)
Comments