Number of rooted trees with a forbidden limb of length 5.

Terms

a(0) =1a(1) =1a(2) =2a(3) =4a(4) =9a(5) =19a(6) =46a(7) =110a(8) =273a(9) =684a(10) =1747a(11) =4505a(12) =11763a(13) =30956a(14) =82153a(15) =219437a(16) =589747a(17) =1593170a(18) =4324445a(19) =11787195a(20) =32251520a(21) =88548011a(22) =243877256a(23) =673605521a(24) =1865445693a(25) =5178574184a(26) =14408195935a(27) =40170674295a(28) =112213616851