A126532 Number of base 11 n-digit numbers with adjacent digits differing by five or less.

1, 11, 91, 781, 6691, 57343, 491429, 4211559, 36093157, 309319197, 2650872719, 22718040927, 194694139719, 1668533310731, 14299369323775, 122545928057115, 1050221456858969, 9000422339067177, 77133829015319501

Offset: 0

Author

R. H. Hardin, Dec 28 2006

Keywords

• nonn
• base

Comments

[Empirical] a(base,n)=a(base-1,n)+11^(n-1) for base>=5n-4; a(base,n)=a(base-1,n)+11^(n-1)-2 when base=5n-5.

Crossrefs

Cf. Base 11 differing by four or less A126506, three or less A126479, two or less A126398, one or less A126365.

Formula

G.f.: (1+3*x-3*x^2-4*x^3+x^4+x^5) / ((1+x)*(1-9*x+3*x^2+6*x^3-x^4-x^5)) (conjectured). - Colin Barker, Jul 17 2017