OFFSET
1,1
LINKS
FORMULA
G.f.: x*(3+x) / ( (x-1)*(9*x-1)*(1+x) ). - R. J. Mathar, Apr 27 2015
a(n) = 7*9^n/20 -1/4 +(-1)^(n+1)/10. - R. J. Mathar, Apr 27 2015
MATHEMATICA
With[{c=PadLeft[{}, 20, {3, 1}]}, Table[FromDigits[Take[c, n], 9], {n, 20}]] (* Harvey P. Dale, Oct 15 2011 *)
CROSSREFS
KEYWORD
nonn,base,easy
AUTHOR
STATUS
approved