OFFSET
0,5
LINKS
Reinhard Zumkeller, Table of n, a(n) for n = 0..1000
EXAMPLE
MATHEMATICA
f[n_]:= (n+1)*f[n-4]; f[0]=1; f[1]=1; f[2]=1; f[3]=1; Table[f[n], {n, 0, 40}]
PROG
(Haskell)
a081407 n = a081408_list !! n
a081407_list = 1 : 1 : 1 : 1 : zipWith (*) [5..] a081407_list
-- Reinhard Zumkeller, Jan 05 2012
(PARI) a(n) = if(n<4, 1, (n+1)*a(n-4) );
vector(35, n, a(n-1)) \\ G. C. Greubel, Aug 24 2019
(Magma) a:= func< n | n le 3 select 1 else n in [4..6] select n+1 else (n+1)*Self(n-3) >;
[a(n): n in [0..35]]; // G. C. Greubel, Aug 24 2019
(Sage)
def a(n):
if n<4: return 1
elif 4<= n <= 6: return n+1
else: return (n+1)*a(n-4)
[a(n) for n in (0..35)] # G. C. Greubel, Aug 24 2019
(GAP)
a:= function(k)
if k<4 then return 1;
elif k<7 then return k+1;
else return (k+1)*a(k-4);
fi;
end;
List([0..35], n-> a(n) ); # G. C. Greubel, Aug 24 2019
CROSSREFS
KEYWORD
nonn
AUTHOR
Labos Elemer, Apr 01 2003
STATUS
approved