Number of permutations of 1..n with displacements restricted to {-6,-5,-4,-2,0,1,3}.

Terms

a(0) =1a(1) =1a(2) =2a(3) =4a(4) =13a(5) =35a(6) =111a(7) =293a(8) =718a(9) =1741a(10) =4273a(11) =10855a(12) =27633a(13) =71187a(14) =182287a(15) =465019a(16) =1180545a(17) =2992281a(18) =7598016a(19) =19309456a(20) =49129136a(21) =125000325a(22) =318018255a(23) =808823885a(24) =2056605339a(25) =5229131690a(26) =13296028742a(27) =33810904043a(28) =85982027049a(29) =218658167715