login

Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.

a(0)=7; a(1)=11; a(2)=13; a(3)=17; a(n) = |a(n-2)+a(n-3)-a(n-4)|.
0

%I #4 Mar 30 2012 17:34:14

%S 7,11,13,17,17,19,21,19,23,21,21,25,19,25,23,19,29,17,25,27,13,35,15,

%T 21,37,1,43,17,7,59,19,49,71,9,101,31,39,123,31,131,115,39,215,23,139,

%U 199,53,315,113,169,375,33,431,239,89,637,103,487,651,47,1035,211,431,1199

%N a(0)=7; a(1)=11; a(2)=13; a(3)=17; a(n) = |a(n-2)+a(n-3)-a(n-4)|.

%C Has an interesting and irregular behavior.

%t a[0] = 7; a[1] = 11; a[2] = 13; a[3] = 17; a[n_Integer?Positive] := a[n] = Abs[ a[n - 2] + a[n - 3] - a[n - 4]]; Table[ a[n], {n, 0, 65}]

%K nonn

%O 0,1

%A _Roger L. Bagula_, Mar 21 2005

%E More terms from _Robert G. Wilson v_, Apr 13 2005