A126479 Number of base 11 n-digit numbers with adjacent digits differing by three or less.

1, 11, 65, 399, 2473, 15381, 95757, 596341, 3714153, 23133309, 144085281, 897434333, 5589669241, 34815260805, 216846906193, 1350631326317, 8412409590489, 52396708044853, 326352989158113, 2032690173290461

Offset: 0

Author

R. H. Hardin, Dec 27 2006

Keywords

• nonn
• base

Comments

[Empirical] a(base,n)=a(base-1,n)+7^(n-1) for base>=3n-2; a(base,n)=a(base-1,n)+7^(n-1)-2 when base=3n-3.

Crossrefs

Cf. Base 11 differing by two or less A126398, one or less A126365.

Formula

G.f.: (1+4*x-10*x^2-16*x^3+6*x^4+8*x^5) / (1-7*x+2*x^2+18*x^3-2*x^4-8*x^5) (conjectured). - Colin Barker, Jul 17 2017