Number of 4-Motzkin paths of length n with no level steps at even level.

A257390

Number of 4-Motzkin paths of length n with no level steps at even level.

Terms

    a(0) =1a(1) =0a(2) =1a(3) =4a(4) =18a(5) =80a(6) =357a(7) =1596a(8) =7150a(9) =32096a(10) =144362a(11) =650568a(12) =2937316a(13) =13286368a(14) =60205805a(15) =273290988a(16) =1242639446a(17) =5659468736a(18) =25816338046a(19) =117945079736a(20) =539646216188

External references