OFFSET
1,1
REFERENCES
H. I. Okagbue, M. O. Adamu, S. A. Bishop and A. A. Opanuga, Properties of Sequences Generated by Summing the Digits of Cubed Positive Integers, Indian Journal Of Natural Sciences, Vol. 6 / Issue 32 / October 2015.
LINKS
Colin Barker, Table of n, a(n) for n = 1..1000
Index entries for linear recurrences with constant coefficients, signature (1,0,0,0,0,1,-1).
FORMULA
From Colin Barker, Aug 26 2016: (Start)
a(n) = a(n-1)+a(n-6)-a(n-7) for n>7.
G.f.: x*(2+x+x^2+x^3+x^4+x^5+2*x^6) / ((1-x)^2*(1+x)*(1-x+x^2)*(1+x+x^2)). (End)
MATHEMATICA
DeleteCases[Range[120], _?(MemberQ[{0, 1, 8}, Mod[#, 9]]&)] (* Harvey P. Dale, Oct 08 2017 *)
PROG
(PARI) Vec(x*(2+x+x^2+x^3+x^4+x^5+2*x^6)/((1-x)^2*(1+x)*(1-x+x^2)*(1+x+x^2)) + O(x^100)) \\ Colin Barker, Aug 26 2016
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Aug 26 2016
STATUS
approved