A126498 - OEIS

%I #5 Mar 31 2012 12:35:06

%S 1,30,198,1330,8990,60998,414910,2827298,19292018,131778306,900905082,

%T 6163326750,42189104748,288930449010,1979525532152,13566774085658,

%U 93007355721960,637770486097522,4374235089178342,30006615117630438

%N Number of base 30 n-digit numbers with adjacent digits differing by three or less.

%C [Empirical] a(base,n)=a(base-1,n)+7^(n-1) for base>=3n-2; a(base,n)=a(base-1,n)+7^(n-1)-2 when base=3n-3

%o (S/R) stvar $[N]:(0..M-1) init $[]:=0 asgn $[]->{*} kill +[i in 0..N-2](($[i]`-$[i+1]`>3)+($[i+1]`-$[i]`>3))

%Y Cf. Base 30 differing by two or less A126417, one or less A126384.

%K nonn,base

%O 0,2

%A _R. H. Hardin_, Dec 27 2006