OFFSET
0,2
COMMENTS
[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
FORMULA
Empirical G.f.: -(3*x^6+22*x^5-25*x^4-34*x^3+35*x^2-5*x-1) / (x^6+6*x^5-11*x^4-6*x^3+15*x^2-7*x+1). [Colin Barker, Nov 26 2012]
PROG
(S/R) stvar $[N]:(0..M-1) init $[]:=0 asgn $[]->{*} kill +[i in 0..N-2](($[i]`-$[i+1]`>1)+($[i+1]`-$[i]`>1))
CROSSREFS
KEYWORD
nonn,base
AUTHOR
R. H. Hardin, Dec 26 2006
STATUS
approved