The number of order-preserving partial isometries (of an n-chain) of fix zero (fix of alpha = 0). Equivalently, the number of order-preserving partial derangement isometries (of an n-chain).
A183155
The number of order-preserving partial isometries (of an n-chain) of fix zero (fix of alpha = 0). Equivalently, the number of order-preserving partial derangement isometries (of an n-chain).
Terms
- a(0) =1a(1) =1a(2) =3a(3) =9a(4) =23a(5) =53a(6) =115a(7) =241a(8) =495a(9) =1005a(10) =2027a(11) =4073a(12) =8167a(13) =16357a(14) =32739a(15) =65505a(16) =131039a(17) =262109a(18) =524251a(19) =1048537a(20) =2097111a(21) =4194261a(22) =8388563a(23) =16777169a(24) =33554383a(25) =67108813a(26) =134217675a(27) =268435401a(28) =536870855a(29) =1073741765
External references
- oeis: A183155