Number of nonnegative walks of n steps with step sizes 1 and 2, starting and ending at 0.
A187430
Number of nonnegative walks of n steps with step sizes 1 and 2, starting and ending at 0.
Terms
- a(0) =1a(1) =0a(2) =2a(3) =2a(4) =11a(5) =24a(6) =93a(7) =272a(8) =971a(9) =3194a(10) =11293a(11) =39148a(12) =139687a(13) =497756a(14) =1798002a(15) =6517194a(16) =23807731a(17) =87336870a(18) =322082967a(19) =1192381270a(20) =4431889344a(21) =16527495396a(22) =61831374003a(23) =231973133544a(24) =872598922407
External references
- oeis: A187430