Number of horizontal steps in the valleys of all bargraphs having semiperimeter n (n >=2).
A278135
Number of horizontal steps in the valleys of all bargraphs having semiperimeter n (n >=2).
Terms
- a(0) =0a(1) =0a(2) =0a(3) =0a(4) =1a(5) =9a(6) =51a(7) =236a(8) =979a(9) =3805a(10) =14190a(11) =51488a(12) =183333a(13) =644121a(14) =2241127a(15) =7741378a(16) =26593899a(17) =90971184a(18) =310159487a(19) =1054693058a(20) =3578948942a(21) =12124108632a(22) =41015411703a(23) =138597840864a(24) =467913141789
External references
- oeis: A278135