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 A126530 Number of base 9 n-digit numbers with adjacent digits differing by five or less. 0
 1, 9, 69, 541, 4231, 33101, 258953, 2025831, 15848391, 123984439, 969949627, 7588067405, 59362636295, 464403174075, 3633098554089, 28422297349753, 222352070721709, 1739494972761653, 13608340819322255, 106460175369651261 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS [Empirical] a(base,n)=a(base-1,n)+11^(n-1) for base>=5n-4; a(base,n)=a(base-1,n)+11^(n-1)-2 when base=5n-5. LINKS Table of n, a(n) for n=0..19. FORMULA Conjectures from Colin Barker, Jun 01 2017: (Start) G.f.: (1 + 2*x - x^2 - x^3) / ((1 + x)*(1 - 8*x + x^2 + 3*x^3)). a(n) = 7*a(n-1) + 7*a(n-2) - 4*a(n-3) - 3*a(n-4) for n>3. (End) PROG (S/R) stvar \$[N]:(0..M-1) init \$[]:=0 asgn \$[]->{*} kill +[i in 0..N-2]((\$[i]`-\$[i+1]`>5)+(\$[i+1]`-\$[i]`>5)) CROSSREFS Cf. Base 9 differing by four or less A126504, three or less A126477, two or less A126396, one or less A126363. Sequence in context: A299915 A287818 A297222 * A351810 A152273 A217452 Adjacent sequences: A126527 A126528 A126529 * A126531 A126532 A126533 KEYWORD nonn,base AUTHOR R. H. Hardin, Dec 28 2006 STATUS approved

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Last modified September 28 20:32 EDT 2023. Contains 365737 sequences. (Running on oeis4.)