cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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A383336 Smallest number with shortest addition-multiplication-exponentiation chain of length n.

Original entry on oeis.org

1, 2, 3, 5, 7, 13, 23, 79, 214, 1418, 5991
Offset: 0

Views

Author

Pontus von Brömssen, Apr 27 2025

Keywords

Comments

For n >= 1, the largest number with shortest addition-multiplication-exponentiation chain of length n is A173566(n).

Examples

			a(7) = 79 because all smaller numbers have addition-multiplication-exponentiation chains of length at most 6, but the shortest chain for 79 has length 7. One such chain is (1, 2, 3, 5, 32, 37, 42, 79). (There are also such chains that do not use exponentiation, such as (1, 2, 3, 4, 5, 15, 75, 79).)

Crossrefs

Cf. A003064, A173566, A383001, A383142, A383335, A383337.

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

Original entry on oeis.org

1, 1, 2, 7, 45, 485
Offset: 0

Views

Author

Pontus von Brömssen, Apr 27 2025

Keywords

Examples

			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.
Showing 1-2 of 2 results.

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