A335280 Lexicographically earliest sequence of distinct positive terms whose Recamán transform has only distinct values.

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 26, 24, 25, 27, 28, 29, 30, 32, 31, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67

Offset: 1

Author

Rémy Sigrist, May 30 2020

Keywords

• nonn

Comments

The Recamán transform of a sequence {b(n), n>0} is the sequence {r(n), n>=0} defined as follows: r(0) = 0; for n > 0, r(n) = r(n-1) - b(n) if nonnegative and not already in the sequence, otherwise r(n) = r(n-1) + b(n).

The Recamán transform of this sequence corresponds to A118201.

Links

• Rémy Sigrist, Table of n, a(n) for n = 1..10000
• Rémy Sigrist, Pinplot of (n, a(n)-n) for n = 1..100000
• Rémy Sigrist, PARI program for A335280
• Index entries for sequences related to Recamán's sequence

Crossrefs

Cf. A005132, A118201.

Programs

PARI

See Links section.

Formula

a(n) = abs(A118201(n)-A118201(n-1)).