Number of Dyck n-paths all of whose ascents have lengths equal to 1 (mod 7).

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =1a(6) =1a(7) =1a(8) =2a(9) =10a(10) =46a(11) =166a(12) =496a(13) =1288a(14) =3004a(15) =6437a(16) =12895a(17) =24583a(18) =45799a(19) =87211a(20) =180235a(21) =420547a(22) =1087220a(23) =2941931a(24) =7927664a(25) =20705636a(26) =51886966a(27) =124660576a(28) =288445186a(29) =648173927