Many excellent designs for a new banner were submitted. We will use the best of them in rotation.
0,2
Alois P. Heinz, Table of n, a(n) for n = 0..200
b:= proc(n) option remember; `if`(n>0, b(n-1), 0) + combinat[bell](n) end:
a:= proc(n) option remember; `if`(n>0, a(n-1), 0) + b(n) end:
seq (a(n), n=0..30); # Alois P. Heinz, Apr 20 2012
Sequence in context: A147321 A103030 A001698 * A009337 A036567 A018023
Adjacent sequences: A029758 A029759 A029760 * A029762 A029763 A029764
nonn
N. J. A. Sloane.
approved
