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

Terms

a(0) =1a(1) =1a(2) =1a(3) =4a(4) =13a(5) =35a(6) =89a(7) =192a(8) =418a(9) =971a(10) =2336a(11) =5654a(12) =13472a(13) =31741a(14) =74468a(15) =175022a(16) =413210a(17) =977502a(18) =2311729a(19) =5460828a(20) =12889416a(21) =30420888a(22) =71817384a(23) =169592184a(24) =400517287a(25) =945825180a(26) =2233383719a(27) =5273484497a(28) =12451877435a(29) =29402388773