Number of 3 X 3 symmetric stochastic matrices under row and column permutations.

Terms

a(0) =1a(1) =1a(2) =2a(3) =4a(4) =6a(5) =8a(6) =12a(7) =16a(8) =21a(9) =27a(10) =34a(11) =42a(12) =52a(13) =62a(14) =74a(15) =88a(16) =103a(17) =119a(18) =138a(19) =158a(20) =180a(21) =204a(22) =230a(23) =258a(24) =289a(25) =321a(26) =356a(27) =394a(28) =434a(29) =476