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A126366
Number of base 12 n-digit numbers with adjacent digits differing by one or less.
4
1, 12, 34, 98, 284, 826, 2408, 7032, 20562, 60186, 176312, 516844, 1515926, 4448336, 13058280, 38345702, 112633540, 330918226, 972433832, 2858069380, 8401323984, 24698783724, 72618671844, 213530132914, 627917268794
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
Sequence in context: A139635 A124705 A296154 * A199114 A009760 A078194
KEYWORD
nonn,base
AUTHOR
R. H. Hardin, Dec 26 2006
STATUS
approved