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A126514
Number of base 19 n-digit numbers with adjacent digits differing by four or less.
1
1, 19, 151, 1239, 10271, 85611, 715649, 5991499, 50202083, 420816645, 3528266989, 29585656541, 248100670697, 2080601208199, 17448464481771, 146328696766445, 1227167540644629, 10291514720245361, 86308846158006385
OFFSET
0,2
COMMENTS
[Empirical] a(base,n)=a(base-1,n)+9^(n-1) for base>=4n-3; a(base,n)=a(base-1,n)+9^(n-1)-2 when base=4n-4
PROG
(S/R) stvar $[N]:(0..M-1) init $[]:=0 asgn $[]->{*} kill +[i in 0..N-2](($[i]`-$[i+1]`>4)+($[i+1]`-$[i]`>4))
CROSSREFS
Cf. Base 19 differing by three or less A126487, two or less A126406, one or less A126373.
Sequence in context: A293116 A066668 A111884 * A168025 A160431 A010825
KEYWORD
nonn,base
AUTHOR
R. H. Hardin, Dec 28 2006
STATUS
approved