For n even a(n) = a(n-1) + 10*a(n-2), for n odd a(n) = a(n-3) + 10 a(n-2); with a(1) = 0, a(2) = 1.

A161999

For n even a(n) = a(n-1) + 10*a(n-2), for n odd a(n) = a(n-3) + 10 a(n-2); with a(1) = 0, a(2) = 1.

Terms

    a(0) =0a(1) =1a(2) =1a(3) =10a(4) =20a(5) =101a(6) =301a(7) =1030a(8) =4040a(9) =10601a(10) =51001a(11) =110050a(12) =620060a(13) =1151501a(14) =7352101a(15) =12135070a(16) =85656080a(17) =128702801a(18) =985263601a(19) =1372684090a(20) =11225320100a(21) =14712104501a(22) =126965305501a(23) =158346365110

External references