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A125406
Number of base 18 circular n-digit numbers with adjacent digits differing by 6 or less.
0
1, 18, 192, 1740, 18140, 193148, 2099982, 23097358, 255965684, 2849912436, 31823439562, 355996289370, 3986819767538, 44679136012334, 500916612375126, 5617436087092970, 63005662878411156, 706745727675422268
OFFSET
0,2
COMMENTS
[Empirical] a(base,n)=a(base-1,n)+F(6) for base>=6.int(n/2)+1 and F(d) is the largest coefficient in (1+x+...+x^(2d))^n
PROG
(S/R) stvar $[N]:(0..M-1) init $[]:=0 asgn $[]->{*} kill +[i in 0..N-1](($[i]`-$[(i+1)mod N]`>6)+($[(i+1)mod N]`-$[i]`>6))
CROSSREFS
Sequence in context: A259163 A004314 A338099 * A318161 A182311 A181711
KEYWORD
nonn,base
AUTHOR
R. H. Hardin, Dec 28 2006
STATUS
approved