Number of n-step self-avoiding walks on a line, where step X skips X - 1 spaces.

Terms

a(0) =1a(1) =2a(2) =4a(3) =6a(4) =10a(5) =18a(6) =30a(7) =50a(8) =78a(9) =130a(10) =210a(11) =350a(12) =586a(13) =954a(14) =1606a(15) =2588a(16) =4234a(17) =6944a(18) =11342a(19) =18948a(20) =31450a(21) =52206a(22) =85662a(23) =141680a(24) =233040a(25) =385428a(26) =644910a(27) =1072074a(28) =1783342a(29) =2953094