Number of exact 3-colored partitions such that no adjacent parts have the same color.

Terms

a(0) =0a(1) =0a(2) =0a(3) =6a(4) =24a(5) =72a(6) =186a(7) =438a(8) =990a(9) =2142a(10) =4560a(11) =9492a(12) =19620a(13) =40068a(14) =81534a(15) =164892a(16) =332808a(17) =669528a(18) =1345554a(19) =2699448a(20) =5412636a(21) =10843038a(22) =21714972a(23) =43467342a(24) =86995428a(25) =174069306a(26) =348265164a(27) =696694692a(28) =1393652298a(29) =2787646380