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A124948
Number of base 20 circular n-digit numbers with adjacent digits differing by 2 or less.
2
1, 20, 94, 350, 1522, 6670, 29992, 136548, 628362, 2914622, 13606624, 63855108, 300982084, 1423941500, 6758032522, 32161829650, 153427657050, 733475019582, 3513035370640, 16854198764892, 80981882536292, 389635048394172
OFFSET
0,2
COMMENTS
[Empirical] a(base,n)=a(base-1,n)+A005191(n+1) for base>=2.int(n/2)+1.
See A285280 for confirmation of linear recurrence and code to produce sequence. - Ray Chandler, Aug 12 2023.
LINKS
Index entries for linear recurrences with constant coefficients, signature (20, -153, 510, -324, -2336, 4689, 2886, -12910, 616, 16708, -3968, -11524, 3200, 4214, -1060, -745, 140, 50, -4, -1).
PROG
(S/R) stvar $[N]:(0..M-1) init $[]:=0 asgn $[]->{*} kill +[i in 0..N-1](($[i]`-$[(i+1)mod N]`>2)+($[(i+1)mod N]`-$[i]`>2))
CROSSREFS
Cf. Row 20 of A285280.
Sequence in context: A281391 A071092 A144359 * A126407 A158446 A221704
KEYWORD
nonn,base
AUTHOR
R. H. Hardin, Dec 28 2006
STATUS
approved