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A126365
Number of base 11 n-digit numbers with adjacent digits differing by one or less.
4
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
0,2
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]
PROG
(S/R) stvar $[N]:(0..M-1) init $[]:=0 asgn $[]->{*} kill +[i in 0..N-2](($[i]`-$[i+1]`>1)+($[i+1]`-$[i]`>1))
CROSSREFS
Sequence in context: A072673 A250461 A259508 * A082102 A199112 A299782
KEYWORD
nonn,base
AUTHOR
R. H. Hardin, Dec 26 2006
STATUS
approved