OFFSET
1,4
COMMENTS
Let a_i(n) = n - a_i(a_i(n-i)) - a_i(n-a_i(n-i)). This sequence is generated by a_2(n) with initial conditions 1, 1.
LINKS
Altug Alkan, Proof of basic property
FORMULA
a(n+1) - a(n) = 0 or 1 for all n >= 1 and a(n) hits every positive integer.
MAPLE
a:=proc(n) option remember: if n<3 then 1 else n-procname(procname(n-2))-procname(n-procname(n-2)) fi; end: seq(a(n), n=1..100); # Muniru A Asiru, Jun 26 2018
PROG
(PARI) a=vector(99); a[1]=a[2]=1; for(n=3, #a, a[n] = n-a[a[n-2]]-a[n-a[n-2]]); a
(GAP) a:=[1, 1];; for n in [3..100] do a[n]:=n-a[a[n-2]]-a[n-a[n-2]]; od; a; # Muniru A Asiru, Jun 26 2018
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Altug Alkan, Jun 21 2018
STATUS
approved