Number of (s(0), s(1), ..., s(2n)) such that 0 < s(i) < 9 and |s(i) - s(i-1)| = 1 for i = 1,2,...,2n, s(0) = 1, s(2n) = 3.

A094826

Number of (s(0), s(1), ..., s(2n)) such that 0 < s(i) < 9 and |s(i) - s(i-1)| = 1 for i = 1,2,...,2n, s(0) = 1, s(2n) = 3.

Terms

    a(0) =1a(1) =3a(2) =9a(3) =28a(4) =90a(5) =297a(6) =1000a(7) =3417a(8) =11799a(9) =41041a(10) =143472a(11) =503262a(12) =1769365a(13) =6230304a(14) =21960801a(15) =77461435a(16) =273351705a(17) =964918116a(18) =3406804786a(19) =12029917377a(20) =42483179304a(21) =150036624217a(22) =529901048943

External references