Number of base 21 circular n-digit numbers with adjacent digits differing by 1 or less.

A124714

Number of base 21 circular n-digit numbers with adjacent digits differing by 1 or less.

Terms

    a(0) =1a(1) =21a(2) =61a(3) =141a(4) =377a(5) =1001a(6) =2737a(7) =7553a(8) =21073a(9) =59217a(10) =167441a(11) =475793a(12) =1357637a(13) =3887541a(14) =11165509a(15) =32152901a(16) =92802433a(17) =268398401a(18) =777651553a(19) =2256800033a(20) =6558953917a(21) =19087539437a(22) =55614451789a(23) =162219429293a(24) =473648632141

External references