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A126411
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Number of base 24 n-digit numbers with adjacent digits differing by two or less.
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5
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1, 24, 114, 550, 2668, 12986, 63348, 309524, 1514230, 7415030, 36339360, 178207260, 874402930, 4292397700, 21079558088, 103555346934, 508877542076, 2501307731338, 12297585994658, 60472695897300, 297423291148782
(list;
graph;
refs;
listen;
history;
text;
internal format)
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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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FORMULA
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G.f.: -(8*x^12 +49*x^11 -117*x^10 -525*x^9 +450*x^8 +1346*x^7 -678*x^6 -1203*x^5 +458*x^4 +302*x^3 -145*x^2 +11*x +1) / (2*x^12 +11*x^11 -33*x^10 -115*x^9 +150*x^8 +286*x^7 -260*x^6 -237*x^5 +190*x^4 +38*x^3 -53*x^2 +13*x -1). - Alois P. Heinz, Sep 25 2015
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MAPLE
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b:= proc(n, i) option remember; `if`(n=0, 1, add(
`if`(i=0 or abs(i-j)<3, b(n-1, j), 0), j=1..24))
end:
a:= n-> b(n, 0):
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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 24 differing by one or less A126378.
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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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