A376638 a(n) is the number of n-digit numbers in A376637.

2, 4, 4, 6, 8, 4, 12, 8, 8, 12, 20, 0, 16, 16, 12, 24, 16, 8, 12, 16, 32, 12, 20, 32, 24, 16, 16, 12, 16, 20, 40, 40, 8, 28, 44, 20, 44, 28, 20, 24, 20, 20, 16, 32, 20, 44, 44, 56, 28, 28, 20, 60, 52, 24, 56, 56, 20, 36, 36, 32, 24, 24, 32, 24, 16, 60, 16, 32

Offset

1,1

Comments

All terms are even: if a word w belongs to A376637, then replacing 1's by 2's and 2's by 1's in w yields another word in A376637.

a(n)/2 is the number of terms of A376637 with digital sum n.

Links

Rémy Sigrist, Table of n, a(n) for n = 1..8192

Rémy Sigrist, C++ program

Index entries for sequences related to Kolakoski sequence

Example

Sequence A376637 begins: 1, 2,  11, 12, 21, 22,  112, 122, 211, 221,  1121.
So a(1) = 2, a(2) = 4, a(3) = 4.

Prog

(C++) // See Links section.

Crossrefs

Cf. A007782, A376637.

Sequence in context: A038669 A288573 A288574 * A135692 A089003 A132118

Adjacent sequences: A376635 A376636 A376637 * A376640 A376641 A376642

Keyword

nonn

Author

Rémy Sigrist, Sep 30 2024

Status

approved