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A126413
Number of base 26 n-digit numbers with adjacent digits differing by two or less.
3
1, 26, 124, 600, 2918, 14236, 69598, 340774, 1670480, 8196280, 40245610, 197738510, 972059180, 4780678950, 23520964308, 115762376468, 569912653284, 2806482718416, 13823453975028, 68101963757630, 335568968553598
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
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 26 differing by one or less A126380.
Sequence in context: A296325 A183066 A124954 * A246032 A044358 A044739
KEYWORD
nonn,base
AUTHOR
R. H. Hardin, Dec 28 2006
STATUS
approved