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A125438
Number of base 26 circular n-digit numbers with adjacent digits differing by 7 or less.
0
1, 26, 334, 3554, 43902, 553306, 7135630, 93271834, 1231458766, 16376454818, 218938689224, 2938429752768, 39550154759946, 533443662253450, 7205953681467518, 97448916863238514, 1318905084028233358
OFFSET
0,2
COMMENTS
[Empirical] a(base,n)=a(base-1,n)+F(7) for base>=7.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]`-$[(i+1)mod N]`>7)+($[(i+1)mod N]`-$[i]`>7))
CROSSREFS
Sequence in context: A022621 A085743 A205494 * A126919 A035708 A252826
KEYWORD
nonn,base
AUTHOR
R. H. Hardin, Dec 28 2006
STATUS
approved