A078451 a(1)=1, a(n) = ceiling(n/a(a(n-1))).

1, 2, 2, 2, 3, 3, 4, 4, 5, 4, 6, 4, 7, 4, 8, 4, 9, 4, 10, 5, 7, 6, 8, 6, 9, 6, 9, 6, 10, 8, 8, 8, 9, 7, 9, 8, 10, 10, 10, 10, 11, 7, 11, 8, 12, 12, 12, 12, 13, 8, 13, 8, 14, 14, 14, 14, 15, 8, 15, 8, 16, 16, 16, 16, 17, 8, 17, 8, 18, 18, 18, 18, 19, 8, 19, 8, 20, 16, 20, 16, 21, 12, 21, 12, 22

Offset

1,2

Comments

If u(1)=1 u(n)=ceiling(n/u(n-1)) then u(2k)=2 and u(2k+1)=k.

Links

Michael De Vlieger, Table of n, a(n) for n = 1..10000

Mathematica

Nest[Append[#, Ceiling[(Length[#] + 1)/#[[#[[-1]] ]] ]] &, {1}, 84] (* Michael De Vlieger, Jul 04 2019 *)

Crossrefs

Sequence in context: A285760 A025778 A294622 * A332247 A341168 A071824

Adjacent sequences: A078448 A078449 A078450 * A078452 A078453 A078454

Keyword

nonn

Author

Benoit Cloitre, Dec 31 2002

Status

approved