0,4

Alois P. Heinz, Table of n, a(n) for n = 0..65536

Alois P. Heinz, Log plot of n, a(n) for n = 0..2^20

b:= proc() 0 end:

a:= proc(n) option remember; local t;

t:= `if`(n<2, n, b(a(b(a(n-1)))));

b(t):= b(t)+1; t

end:

seq(a(n), n=0..200); # Alois P. Heinz, Jul 24 2018

Cf. A316774, A317015, A317127.

Sequence in context: A249616 A307408 A233539 * A321576 A304101 A278636

Adjacent sequences: A317220 A317221 A317222 * A317224 A317225 A317226

nonn

Altug Alkan, Jul 24 2018

approved