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A124784 Number of base 29 circular n-digit numbers with adjacent digits differing by 1 or less. 1
1, 29, 85, 197, 529, 1409, 3865, 10697, 29929, 84329, 239065, 681017, 1947949, 5591069, 16095325, 46453757, 134375449, 389477849, 1130874025, 3288774857, 9577988869, 27930345269, 81543536005, 238325254277, 697235323189 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

[Empirical] a(base,n)=a(base-1,n)+A002426(n+1) for base>=1.int(n/2)+1

a(n) = T(n, 29) where T(n, k) = Sum_{j=1..k} (1+2*cos(j*Pi/(k+1)))^n. These are the number of smooth cyclic words of length n over the alphabet {1,2,..,29}. See theorem 3.3 in Knopfmacher and others, reference in A124696. - Peter Luschny, Aug 13 2012

LINKS

Table of n, a(n) for n=0..24.

PROG

(S/R) stvar $[N]:(0..M-1) init $[]:=0 asgn $[]->{*} kill +[i in 0..N-1](($[i]`-$[(i+1)mod N]`>1)+($[(i+1)mod N]`-$[i]`>1))

CROSSREFS

Sequence in context: A273362 A195314 A323218 * A126383 A032508 A042654

Adjacent sequences:  A124781 A124782 A124783 * A124785 A124786 A124787

KEYWORD

nonn,base

AUTHOR

R. H. Hardin, Dec 28 2006

STATUS

approved

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Last modified March 23 04:46 EDT 2019. Contains 321422 sequences. (Running on oeis4.)