A329202 a(n) = floor(2*log_2(n)) = floor(log_2(n^2)).

0, 2, 3, 4, 4, 5, 5, 6, 6, 6, 6, 7, 7, 7, 7, 8, 8, 8, 8, 8, 8, 8, 9, 9, 9, 9, 9, 9, 9, 9, 9, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12

Offset

1,2

Comments

For n >= 1, a(n+1) is the tree-depth of the n-ladder graph. - Eric W. Weisstein, Jul 01 2026

Links

Table of n, a(n) for n=1..80.

Eric Weisstein's World of Mathematics, Ladder Graph.

Eric Weisstein's World of Mathematics, Tree-Depth.

Mathematica

Table[Floor[2 Log2[n]], {n, 20}] (* Eric W. Weisstein, Jul 01 2026 *)
(* Alternative: *)
Floor[2 Log2[Range[20]]] (* Eric W. Weisstein, Jul 01 2026 *)

Prog

(PARI) a(n)=logint(n^2, 2)

Crossrefs

Cf. A017912, A328911 (has this as row lengths).

Sequence in context: A333262 A218767 A334863 * A318994 A261101 A327704

Adjacent sequences: A329199 A329200 A329201 * A329203 A329204 A329205

Keyword

nonn,easy

Author

M. F. Hasler, Nov 07 2019

Status

approved