Number of rooted identity trees with n nodes and 4 leaves.

Terms

a(0) =2a(1) =11a(2) =40a(3) =109a(4) =254a(5) =524a(6) =998a(7) =1774a(8) =2995a(9) =4833a(10) =7525a(11) =11346a(12) =16659a(13) =23877a(14) =33528a(15) =46203a(16) =62637a(17) =83643a(18) =110213a(19) =143432a(20) =184600a(21) =235129a(22) =296687a(23) =371072a(24) =460382a(25) =566866a(26) =693121a(27) =841917a(28) =1016422a(29) =1220001