A361399 a(n) is the least k such that the binary expansion of n is a self-infiltration of that of k.

0, 1, 2, 1, 2, 5, 2, 3, 4, 5, 2, 5, 2, 5, 6, 3, 4, 9, 10, 5, 4, 5, 10, 11, 4, 5, 6, 5, 6, 13, 6, 7, 8, 9, 18, 9, 4, 9, 10, 11, 4, 9, 10, 5, 10, 5, 22, 11, 4, 9, 10, 5, 10, 5, 6, 11, 12, 13, 6, 13, 6, 13, 14, 7, 8, 17, 18, 9, 18, 9, 18, 19, 8, 9, 10, 19, 10, 21

Offset: 0

Author

Rémy Sigrist, Mar 10 2023

Keywords

• nonn
• base

Comments

See A361398 for the definition of an infiltration (a self-infiltration is an infiltration a of word with itself).

a(n) is the index of the first row of A361401 containing n.

Links

• Rémy Sigrist, Table of n, a(n) for n = 0..8192
• Rémy Sigrist, Colored log-log scatterplot of the first 2^20 terms (the color is function of A070939(a(n)) - A070939(n))
• Rémy Sigrist, PARI program
• Index entries for sequences related to binary expansion of n

Crossrefs

Cf. A020330, A070939, A361398, A361401.

Programs

PARI

See Links section.

Formula

a(n) <= n.

a(A020330(n)) = n.