A124709 Number of base 16 circular n-digit numbers with adjacent digits differing by 1 or less.

1, 16, 46, 106, 282, 746, 2032, 5588, 15538, 43522, 122676, 347528, 988692, 2822836, 8084374, 23214866, 66819298, 192723746, 556887508, 1611815768, 4672057072, 13560785792, 39408774154, 114653288678, 333906950236

Offset: 0

Author

R. H. Hardin, Dec 28 2006

Keywords

• nonn
• base

Comments

[Empirical] a(base,n)=a(base-1,n)+A002426(n+1) for base>=1.int(n/2)+1

a(n) = T(n, 16) where T(n, k) = Sum_{j=1..k} (1+2*cos(j*Pi/(k+1)))^n. These are the number of smooth cyclic words of length n over the alphabet {1,2,..,16}. See theorem 3.3 in Knopfmacher and others, reference in A124696. - Peter Luschny, Aug 13 2012

Links

• OEIS Wiki, Number of base k circular n-digit numbers with adjacent digits differing by d or less