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A126404
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Number of base 17 n-digit numbers with adjacent digits differing by two or less.
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3
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1, 17, 79, 375, 1793, 8611, 41473, 200149, 967355, 4680655, 22667487, 109848049, 532610303, 2583482303, 12535495657, 60839746967, 295338090269, 1433900817213, 6962605102325, 33811619587041, 164207415391765
(list;
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refs;
listen;
history;
text;
internal format)
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OFFSET
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1,2
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COMMENTS
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[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.
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LINKS
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FORMULA
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G.f.: (1+7*x-64*x^2+48*x^3+171*x^4-100*x^5-120*x^6+50*x^7+20*x^8-6*x^9) / (1-10*x+27*x^2+4*x^3-73*x^4+19*x^5+50*x^6-14*x^7-8*x^8+2*x^9) (conjectured). - Colin Barker, Jul 18 2017
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PROG
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(S/R) stvar $[N]:(0..M-1) init $[]:=0 asgn $[]->{*} kill +[i in 0..N-2](($[i]`-$[i+1]`>2)+($[i+1]`-$[i]`>2))
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CROSSREFS
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Cf. Base 17 differing by one or less A126371.
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KEYWORD
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nonn,base
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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