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A126385
Number of base 31 n-digit numbers with adjacent digits differing by one or less.
5
1, 31, 91, 269, 797, 2365, 7025, 20883, 62115, 184845, 550289, 1638775, 4881719, 14545715, 43350415, 129222077, 385262397, 1148802957, 3426077313, 10218944199, 30483682935, 90944672583, 271351287651, 809707376697
OFFSET
0,2
COMMENTS
[Empirical] a(base,n)=a(base-1,n)+3^(n-1) for base>=n; a(base,n)=a(base-1,n)+3^(n-1)-2 when base=n-1
PROG
(S/R) stvar $[N]:(0..M-1) init $[]:=0 asgn $[]->{*} kill +[i in 0..N-2](($[i]`-$[i+1]`>1)+($[i+1]`-$[i]`>1))
CROSSREFS
Sequence in context: A360488 A139700 A124803 * A061155 A098440 A042892
KEYWORD
nonn,base
AUTHOR
R. H. Hardin, Dec 26 2006
STATUS
approved