Number of pebbling configurations with n pebbles.

Terms

a(0) =1a(1) =1a(2) =2a(3) =4a(4) =9a(5) =20a(6) =46a(7) =105a(8) =243a(9) =561a(10) =1301a(11) =3014a(12) =6995a(13) =16227a(14) =37668a(15) =87426a(16) =202961a(17) =471150a(18) =1093819a(19) =2539348a(20) =5895408a(21) =13686805a(22) =31775756a(23) =73771474a(24) =171270732a(25) =397628399a(26) =923150354a(27) =2143222823a(28) =4975795414a(29) =11552012449