OFFSET
1,1
COMMENTS
See scatterplots in Links section to observe the distribution of terms.
LINKS
Altug Alkan, Scatterplot of a(n) for n <= 10^5
Altug Alkan, Alternative scatterplot of a(n) for n <= 10^5
MATHEMATICA
Fold[Append[#1, #1[[#2 - #1[[#2 - 1]] ]] + #1[[#2 - #1[[#2 - 2]] ]]] &, {2, 4, 2, 2}, Range[5, 83]] (* Michael De Vlieger, Oct 30 2017 *)
PROG
(PARI) q=vector(10^5); q[1]=q[3]=q[4]=2; q[2]=4; for(n=5, #q, q[n] = q[n-q[n-1]]+q[n-q[n-2]]); q
CROSSREFS
KEYWORD
nonn
AUTHOR
Altug Alkan, Oct 29 2017
STATUS
approved