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 A126397 Number of base 10 n-digit numbers with adjacent digits differing by two or less. 3
 1, 10, 44, 200, 918, 4236, 19598, 90790, 420870, 1951636, 9051480, 41983154, 194736668, 903293618, 4190003458, 19435777562, 90155141564, 418195731384, 1939853565942, 8998257693932, 41739569773726, 193614349514214 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS [Empirical] a(base,n)=a(base-1,n)+5^(n-1) for base>=2n-1; a(base,n)=a(base-1,n)+5^(n-1)-2 when base=2n-2. LINKS FORMULA Conjectures from Colin Barker, May 31 2017: (Start) G.f.: (1 + 3*x - 15*x^2 + 2*x^3 + x^4) / (1 - 7*x + 11*x^2 - x^4). a(n) = 7*a(n-1) - 11*a(n-2) + a(n-4) for n>4. (End) PROG (S/R) stvar \$[N]:(0..M-1) init \$[]:=0 asgn \$[]->{*} kill +[i in 0..N-2]((\$[i]`-\$[i+1]`>2)+(\$[i+1]`-\$[i]`>2)) CROSSREFS Cf. Base 10 differing by one or less A126364. Sequence in context: A076373 A097215 A281993 * A164607 A200189 A240383 Adjacent sequences:  A126394 A126395 A126396 * A126398 A126399 A126400 KEYWORD nonn,base AUTHOR R. H. Hardin, Dec 28 2006 STATUS approved

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