Number of sequences of n integers p(i), i=0..n-1, with 0 <= p(i) <= 2*i and |p(i) - p(i-1)| <= 2.
A180898
Number of sequences of n integers p(i), i=0..n-1, with 0 <= p(i) <= 2*i and |p(i) - p(i-1)| <= 2.
Terms
- a(0) =1a(1) =3a(2) =12a(3) =51a(4) =226a(5) =1025a(6) =4724a(7) =22022a(8) =103550a(9) =490191a(10) =2333057a(11) =11153428a(12) =53517672a(13) =257600811a(14) =1243270807a(15) =6014482911a(16) =29155412470a(17) =141587439283a(18) =688697290541
External references
- oeis: A180898