OFFSET
0,5
COMMENTS
The sequence is designed so that all the numbers, see A055389 or A006355, except the first two appear twice.
The limiting ratio a(n+1)/a(n) alternates between the golden ratio and one.
Essentially the same as A214927 (except for the first 4 terms and the offset). - Georg Fischer, Oct 01 2018
FORMULA
a(n) = a(n-2)+a(n-4), n > 7.
G.f.: (x^7+1+x-x^6)/(1-x^2-x^4).
MATHEMATICA
a[0] = 1; a[1] = 1; a[2] = 1; a[3] = 1;
a[n_] := a[n] = If[Mod[n, 2] == 0, a[n - 3] + a[n - 4], a[n - 2] + a[n - 3]];
Table[a[n], {n, 0, 50}]
CROSSREFS
KEYWORD
nonn,easy,less
AUTHOR
Roger L. Bagula, Feb 17 2010
EXTENSIONS
Formula added by the Assoc. Editors of the OEIS, Feb 24 2010
STATUS
approved