Number of simple graphs on n vertices up to homotopy equivalence.

Terms

a(0) =1a(1) =1a(2) =2a(3) =4a(4) =8a(5) =15a(6) =27a(7) =46a(8) =77a(9) =126a(10) =204a(11) =325a(12) =515a(13) =806a(14) =1252a(15) =1929a(16) =2953a(17) =4486a(18) =6778a(19) =10176a(20) =15200a(21) =22583a(22) =33394a(23) =49143a(24) =72019a(25) =105089a(26) =152746a(27) =221159a(28) =319070a(29) =458697