%I #7 Mar 31 2012 12:35:01
%S 1,15,115,735,5435,40965,315991,2469909,19495747,154956453,1237813755,
%T 9923510469,79762415747,642295225197,5178982417003,41798669030805,
%U 337575342572995,2727627544083901,22046802610388635,178241899736229829
%N Number of base 15 circular n-digit numbers with adjacent digits differing by 4 or less.
%C [Empirical] a(base,n)=a(base-1,n)+A025014(n+1) for base>=4.int(n/2)+1
%o (S/R) stvar $[N]:(0..M-1) init $[]:=0 asgn $[]->{*} kill +[i in 0..N-1](($[i]`-$[(i+1)mod N]`>4)+($[(i+1)mod N]`-$[i]`>4))
%K nonn,base
%O 0,2
%A _R. H. Hardin_, Dec 28 2006