OFFSET
1,3
FORMULA
a(2n) = 3*a(2n-1) + 2*a(n) for n >= 2; a(2n-1) = 3*a(2n-2) - a(n) for n >= 2
MAPLE
A045695 := proc(n)
if n <=2 then
n-1 ;
elif type(n, 'even') then
3*procname(n-1)+2*procname(n/2) ;
else
3*procname(n-1)-procname((n+1)/2) ;
end if;
end proc: # R. J. Mathar, Oct 04 2014
MATHEMATICA
a[n_] := If[n <= 2, n-1,
If[EvenQ[n], 3*a[n-1] + 2*a[n/2],
3*a[n-1] - a[(n+1)/2]]];
Table[a[n], {n, 1, 27}] (* Jean-François Alcover, Mar 15 2024, after Maple code *)
CROSSREFS
KEYWORD
nonn
AUTHOR
TORSTEN.SILLKE(AT)LHSYSTEMS.COM
STATUS
approved