A394973 a(n) is the smallest k such that A091508(k) = n.

1, 2, 6, 12, 5, 16, 4, 32, 20, 68, 27, 232, 104, 939, 51, 57, 99, 10552, 33, 1864, 304, 8, 7352, 248, 7, 16984, 2584, 3688, 1312, 13744, 40792, 53608, 3352, 54008, 18104, 1144, 680, 980584, 664, 1364, 2744, 1100024, 7480168, 2343784, 152, 808, 449144, 9478904

Offset

1,2

Comments

This sequence is infinite because every positive integer n appears at or before index n! in the sequence A091508; however, we have found only 84 terms. The last and largest term that we know is a(396) = 999999899639187. The first term that we do not know is a(61) (see attached a-file).

a(A394797(n)) < a(k) for all k > A394797(n), where A394797 is the sequence of indices for the record values of A091508.

Links

Table of n, a(n) for n=1..48.

Sam Chapman, Table of n, a(n) for n=1..396, with "?" for unknown values.

Formula

a(n) <= n! for all n. - M. F. Hasler, Apr 10 2026

Example

a(10) = 68 since A091508(68) = 10, and A091508(k) != 10 for all k < 68.

Crossrefs

Cf. A091508, A394797.

Sequence in context: A209386 A205103 A367575 * A165822 A014965 A074259

Adjacent sequences: A394970 A394971 A394972 * A394974 A394975 A394976

Keyword

nonn

Author

Sam Chapman, Apr 08 2026

Status

approved