Number of up steps in all bargraphs of semiperimeter n (n>=2).

Terms

a(0) =1a(1) =3a(2) =10a(3) =32a(4) =102a(5) =326a(6) =1046a(7) =3370a(8) =10899a(9) =35369a(10) =115123a(11) =375705a(12) =1228970a(13) =4028366a(14) =13228516a(15) =43511464a(16) =143329157a(17) =472761015a(18) =1561246112a(19) =5161512902a(20) =17081176912a(21) =56579333508a(22) =187570898065a(23) =622318325281