Number of n X 4 0..1 arrays with rows and columns lexicographically nondecreasing read forwards, and nonincreasing read backwards.

A201371

Number of n X 4 0..1 arrays with rows and columns lexicographically nondecreasing read forwards, and nonincreasing read backwards.

Terms

    a(0) =2a(1) =5a(2) =14a(3) =36a(4) =80a(5) =157a(6) =280a(7) =464a(8) =726a(9) =1085a(10) =1562a(11) =2180a(12) =2964a(13) =3941a(14) =5140a(15) =6592a(16) =8330a(17) =10389a(18) =12806a(19) =15620a(20) =18872a(21) =22605a(22) =26864a(23) =31696a(24) =37150a(25) =43277a(26) =50130a(27) =57764a(28) =66236a(29) =75605

External references