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A125357
Number of base 20 circular n-digit numbers with adjacent digits differing by 4 or less.
0
1, 20, 160, 1040, 7880, 60720, 479296, 3835544, 31025864, 253006376, 2076361620, 17126818652, 141850168856, 1178779027316, 9822495145882, 82032520847910, 686360207228280, 5751457669257720, 48255474860875126, 405286028562477798
OFFSET
0,2
COMMENTS
[Empirical] a(base,n)=a(base-1,n)+A025014(n+1) for base>=4.int(n/2)+1
PROG
(S/R) stvar $[N]:(0..M-1) init $[]:=0 asgn $[]->{*} kill +[i in 0..N-1](($[i]`-$[(i+1)mod N]`>4)+($[(i+1)mod N]`-$[i]`>4))
CROSSREFS
Sequence in context: A324948 A159470 A059601 * A126515 A118676 A067534
KEYWORD
nonn,base
AUTHOR
R. H. Hardin, Dec 28 2006
STATUS
approved