Number of walks within N^2 (the first quadrant of Z^2) starting at (0,0) and consisting of n steps taken from {(-1, -1), (-1, 0), (0, 1), (1, 0)}.
A151279
Number of walks within N^2 (the first quadrant of Z^2) starting at (0,0) and consisting of n steps taken from {(-1, -1), (-1, 0), (0, 1), (1, 0)}.
Terms
- a(0) =1a(1) =2a(2) =5a(3) =15a(4) =45a(5) =143a(6) =467a(7) =1542a(8) =5209a(9) =17747a(10) =61092a(11) =212350a(12) =742252a(13) =2612743a(14) =9243761a(15) =32849712a(16) =117260065a(17) =420007621a(18) =1509519796a(19) =5441576335a(20) =19667601165a(21) =71265365948a(22) =258803411203a(23) =941809569454
External references
- oeis: A151279