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A126482
Number of base 14 n-digit numbers with adjacent digits differing by three or less.
2
1, 14, 86, 546, 3502, 22582, 146000, 945166, 6122674, 39674426, 257126690, 1666543060, 10801947152, 70015705526, 453829551820, 2941656640950, 19067428223036, 123592671411170, 801112565036276, 5192714887319794
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+5*x-27*x^2-21*x^3+35*x^4+8*x^5-5*x^6-x^7) / (1-9*x+13*x^2+25*x^3-21*x^4-10*x^5+3*x^6+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]`-$[i+1]`>3)+($[i+1]`-$[i]`>3))
CROSSREFS
Cf. Base 14 differing by two or less A126401, one or less A126368.
Sequence in context: A372148 A213121 A125324 * A206614 A345107 A321941
KEYWORD
nonn,base
AUTHOR
R. H. Hardin, Dec 27 2006
STATUS
approved