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A126401
Number of base 14 n-digit numbers with adjacent digits differing by two or less.
3
1, 14, 64, 300, 1418, 6736, 32098, 153274, 732980, 3508800, 16808758, 80562042, 386258512, 1852391310, 8885102252, 42623064868, 204486065796, 981089277884, 4707294583320, 22586391528066, 108375512842272, 520021938034950
OFFSET
0,2
COMMENTS
[Empirical] a(base,n)=a(base-1,n)+5^(n-1) for base>=2n-1; a(base,n)=a(base-1,n)+5^(n-1)-2 when base=2n-2.
FORMULA
G.f.: (1+6*x-35*x^2-13*x^3+63*x^4+18*x^5-17*x^6-4*x^7) / (1-8*x+13*x^2+17*x^3-25*x^4-12*x^5+7*x^6+2*x^7) (conjectured). - Colin Barker, Jul 18 2017
PROG
(S/R) stvar $[N]:(0..M-1) init $[]:=0 asgn $[]->{*} kill +[i in 0..N-2](($[i]`-$[i+1]`>2)+($[i+1]`-$[i]`>2))
CROSSREFS
Cf. Base 14 differing by one or less A126368.
Sequence in context: A074354 A212743 A124892 * A275268 A304873 A226754
KEYWORD
nonn,base
AUTHOR
R. H. Hardin, Dec 28 2006
STATUS
approved