A079623 a(1)=a(2)=1, a(3)=4, a(n)=abs(a(n-1)-a(n-2)-a(n-3)).

1, 1, 4, 2, 3, 3, 2, 4, 1, 5, 0, 6, 1, 5, 2, 4, 3, 3, 4, 2, 5, 1, 6, 0, 7, 1, 6, 2, 5, 3, 4, 4, 3, 5, 2, 6, 1, 7, 0, 8, 1, 7, 2, 6, 3, 5, 4, 4, 5, 3, 6, 2, 7, 1, 8, 0, 9, 1, 8, 2, 7, 3, 6, 4, 5, 5, 4, 6, 3, 7, 2, 8, 1, 9, 0, 10, 1, 9, 2, 8, 3, 7, 4, 6, 5, 5, 6, 4, 7, 3, 8, 2, 9, 1, 10, 0, 11, 1, 10, 2, 9, 3, 8

Offset

1,3

Links

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

Formula

a(n*(n-10))=0; Max( a(k) : 1<=k<=n) = floor(sqrt(n+24))

Mathematica

nxt[{a_, b_, c_}]:={b, c, Abs[c-b-a]}; NestList[nxt, {1, 1, 4}, 110][[All, 1]] (* Harvey P. Dale, Aug 12 2020 *)

Prog

(Haskell)
a079623 n = a079623_list !! (n-1)
a079623_list = 1 : 1 : 4 : zipWith3 (\u v w -> abs (w - v - u))
               a079623_list (tail a079623_list) (drop 2 a079623_list)
-- Reinhard Zumkeller, Oct 11 2014

Crossrefs

Cf. A078108, A080096.

Cf. A077623, A077653, A079624, A088226.

Sequence in context: A190874 A307367 A136626 * A177864 A090112 A226087

Adjacent sequences: A079620 A079621 A079622 * A079624 A079625 A079626

Keyword

nonn

Author

Benoit Cloitre, Jan 30 2003

Status

approved