A383337 Number of integers with a shortest addition-multiplication-exponentiation chain of length n.

1, 1, 2, 7, 45, 485

Offset

0,3

Links

Table of n, a(n) for n=0..5.

Example

Only 1 has an addition-multiplication-exponentiation chain of length 0, so a(0) = 1.
Only 2 has a shortest chain of length 1, so a(1) = 1.
3 and 4 have shortest chains of length 2, so a(2) = 2.
5, 6, 8, 9, 16, 27, and 256 have shortest chains of length 3, so a(3) = 7.

Crossrefs

Cf. A003065, A383002, A383143, A383335, A383336.

Sequence in context: A066612 A098637 A162045 * A326878 A153549 A348880

Adjacent sequences: A383334 A383335 A383336 * A383338 A383339 A383340

Keyword

nonn,hard,more

Author

Pontus von Brömssen, Apr 27 2025

Status

approved