Half the number of ways of placing up to n pawns on a length n chessboard row so that the row balances at its middle.
A133406
Half the number of ways of placing up to n pawns on a length n chessboard row so that the row balances at its middle.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =2a(4) =4a(5) =4a(6) =10a(7) =9a(8) =26a(9) =24a(10) =76a(11) =69a(12) =236a(13) =214a(14) =760a(15) =696a(16) =2522a(17) =2326a(18) =8556a(19) =7942a(20) =29504a(21) =27562a(22) =103130a(23) =96862a(24) =364548a(25) =344004a(26) =1300820a(27) =1232567a(28) =4679472a(29) =4449850
External references
- oeis: A133406