OFFSET
0,5
LINKS
Reinhard Zumkeller, Table of n, a(n) for n = 0..10000
FORMULA
a(n)=a(abs(n-a(n-1)))+a(abs(n-a(n-2)))+a(abs(n-a(n-3)), a(j)=0 for j>n.
MATHEMATICA
a[0] = 0; a[1] = a[2] = a[3] = 1; a[n_] := a[n] = Module[{b}, b[j_ /; j > n] = 0; b[j_] := a[j]; b[Abs[n - b[n-1]]] + b[Abs[n - b[n-2]]] + b[Abs[n - b[n-3]]]]; Table[a[n], {n, 0, 100}] (* Jean-François Alcover, Oct 23 2016 *)
PROG
(Haskell)
import Data.List (genericIndex)
a038135 n = genericIndex a038135_list n
a038135_list = 0 : 1 : 1 : 1 : f 1 1 1 4 where
f u v w x = y : f v w y (x + 1) where
y = q (x - u) + q (x - v) + q (x - w)
q z = if abs z >= x then 0 else a038135 $ abs z
-- Reinhard Zumkeller, Sep 21 2014
CROSSREFS
KEYWORD
nice,nonn
AUTHOR
EXTENSIONS
More terms from Larry Reeves (larryr(AT)acm.org), Apr 04 2000
STATUS
approved