OFFSET

0,4

COMMENTS

Let s(n) be the set of terms in the n-th row of A133457 (with s(0) = {}).

a(n) is the least k such that s(n) is the image of s(k) under some nonconstant linear function.

LINKS

Rémy Sigrist, Table of n, a(n) for n = 0..8192

Rémy Sigrist, PARI program

Wikipedia, Similarity (geometry)

FORMULA

EXAMPLE

The first terms, alongside their binary expansions, are:

n a(n) bin(n) bin(a(n))

-- ---- ------ ---------

0 0 0 0

1 1 1 1

2 1 10 1

3 3 11 11

4 1 100 1

5 3 101 11

6 3 110 11

7 7 111 111

8 1 1000 1

9 3 1001 11

10 3 1010 11

11 11 1011 1011

12 3 1100 11

13 11 1101 1011

14 7 1110 111

15 15 1111 1111

16 1 10000 1

PROG

(PARI) See Links section.

CROSSREFS

KEYWORD

nonn,base

AUTHOR

Rémy Sigrist, Oct 15 2022

STATUS

approved