A357987 Lexicographically earliest sequence of positive integers such that no sum of consecutive terms is a square or higher power of an integer.

2, 3, 2, 5, 5, 2, 3, 2, 21, 5, 2, 5, 5, 5, 7, 6, 5, 6, 6, 7, 11, 24, 2, 13, 5, 6, 35, 7, 10, 34, 6, 15, 2, 28, 10, 2, 5, 14, 19, 2, 5, 28, 2, 3, 2, 35, 2, 18, 6, 11, 3, 3, 37, 2, 5, 26, 29, 33, 42, 13, 5, 5, 10, 11, 13, 21, 18, 5, 10, 5, 6, 7, 24, 20, 3, 15

Offset

1,1

Comments

This sequence is a variant of A357579 where we allow duplicates.

This sequence is well defined as we have arbitrary large gaps in A001597.

Links

Table of n, a(n) for n=1..76.

Rémy Sigrist, C program

Example

For n = 1:
- 2 is not a perfect power,
- so a(1) = 2.
For n = 2:
- 2 + 2 is a perfect power,
- neither 2 + 3 nor 3 are perfect powers,
- so a(2) = 3.
For n = 3:
- none of 2 + 3 + 2, 3 + 2, 2 is a perfect power,
- so a(3) = 2.

Prog

(C) See Links section.

Crossrefs

Cf. A001597, A007916, A357579.

Sequence in context: A075274 A331309 A178144 * A135737 A125179 A141821

Adjacent sequences: A357984 A357985 A357986 * A357988 A357989 A357990

Keyword

nonn

Author

Rémy Sigrist, Oct 23 2022

Status

approved