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A126479
Number of base 11 n-digit numbers with adjacent digits differing by three or less.
2
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.
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
KEYWORD
nonn,base
AUTHOR
R. H. Hardin, Dec 27 2006
STATUS
approved