A126379 - OEIS

%I #5 Mar 31 2012 12:35:05

%S 1,25,73,215,635,1879,5567,16509,48993,145479,432191,1284481,3818837,

%T 11357069,33784477,100524263,299168955,890522631,2651236335,

%U 7894421265,23510114133,70023966177,208589168433,621421019043,1851508693479

%N Number of base 25 n-digit numbers with adjacent digits differing by one or less.

%C [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

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

%K nonn,base

%O 0,2

%A _R. H. Hardin_, Dec 26 2006