A126365 Number of base 11 n-digit numbers with adjacent digits differing by one or less.

1, 11, 31, 89, 257, 745, 2165, 6303, 18375, 53625, 156629, 457795, 1338779, 3916897, 11463989, 33563035, 98286811, 287884769, 843365485, 2471005371, 7240717539, 21219286113, 62189049541, 182274146987, 534268171099

Offset: 0

Author

R. H. Hardin, Dec 26 2006

Keywords

• nonn
• base

Comments

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

Formula

Empirical G.f.: -(6*x^6+4*x^5-34*x^4-6*x^3+26*x^2-5*x-1) / ((x^2+2*x-1)*(2*x^4-4*x^3-2*x^2+4*x-1)). [Colin Barker, Nov 26 2012]