%I
%S 1,20,94,450,2168,10486,50848,247024,1201730,5852530,28526860,
%T 139144760,679090456,3315836420,16196773236,79141717426,386812618952,
%U 1891013450430,9246370600422,45218609940844,221167392509842
%N Number of base 20 ndigit numbers with adjacent digits differing by two or less.
%C [Empirical] a(base,n)=a(base1,n)+5^(n1) for base>=2n1; a(base,n)=a(base1,n)+5^(n1)2 when base=2n2
%o (S/R) stvar $[N]:(0..M1) init $[]:=0 asgn $[]>{*} kill +[i in 0..N2](($[i]`$[i+1]`>2)+($[i+1]`$[i]`>2))
%Y Cf. Base 20 differing by one or less A126374.
%K nonn,base
%O 0,2
%A _R. H. Hardin_, Dec 28 2006
