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

0,2

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.

Links

Table of n, a(n) for n=0..19.

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

Prog

(S/R) stvar $[N]:(0..M-1) init $[]:=0 asgn $[]->{*} kill +[i in 0..N-2](($[i]`-$[i+1]`>3)+($[i+1]`-$[i]`>3))

Crossrefs

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

Sequence in context: A036601 A125321 A054490 * A260151 A139611 A154617

Adjacent sequences: A126476 A126477 A126478 * A126480 A126481 A126482

Keyword

nonn,base

Author

R. H. Hardin, Dec 27 2006

Status

approved