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A126408
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Number of base 21 n-digit numbers with adjacent digits differing by two or less.
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3
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1, 21, 99, 475, 2293, 11111, 53973, 262649, 1279855, 6243155, 30479985, 148910385, 727918557, 3559976043, 17417455619, 85244931269, 417326666085, 2043565752795, 10008988327829, 49030629716903, 240219997723397
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OFFSET
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0,2
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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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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 21 differing by one or less A126375.
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KEYWORD
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nonn,base
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AUTHOR
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STATUS
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approved
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