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Number of base 19 n-digit numbers with adjacent digits differing by five or less.
0

%I #7 Mar 31 2012 12:35:06

%S 1,19,179,1749,17269,171283,1701677,16916769,168213851,1672806301,

%T 16635830987,165443231083,1645339968293,16363006476491,

%U 162731213670657,1618373433642625,16094839928704707,160064344144932989

%N Number of base 19 n-digit numbers with adjacent digits differing by five or less.

%C [Empirical] a(base,n)=a(base-1,n)+11^(n-1) for base>=5n-4; a(base,n)=a(base-1,n)+11^(n-1)-2 when base=5n-5

%o (S/R) stvar $[N]:(0..M-1) init $[]:=0 asgn $[]->{*} kill +[i in 0..N-2](($[i]`-$[i+1]`>5)+($[i+1]`-$[i]`>5))

%Y Cf. Base 19 differing by four or less A126514, three or less A126487, two or less A126406, one or less A126373.

%K nonn,base

%O 0,2

%A _R. H. Hardin_, Dec 28 2006