Number of permutations of 0..n-1 which are binary Gray codes.

Terms

a(0) =1a(1) =2a(2) =2a(3) =8a(4) =4a(5) =16a(6) =24a(7) =144a(8) =36a(9) =164a(10) =192a(11) =1168a(12) =976a(13) =5688a(14) =10656a(15) =91392a(16) =11424a(17) =67032a(18) =61840a(19) =403568a(20) =258956a(21) =1589080a(22) =2520324a(23) =22646880a(24) =10898976a(25) =67039504a(26) =93326800a(27) =819193248a(28) =924489888a(29) =7399407552