A352571 Index of n in A338833, or -1 if n does not appear there.

1, -1, 2, -1, 13, 3, 17, -1, 5, 8, 25, 4, 9, 14, 45, -1, 6, 7, 21, 10, 24, 28, 50, 15, 20, 40, 34, 31, 41, 35, 80, -1, 12, 22, 68, 23, 42, 55, 63, 26, 30, 56, 64, 51, 75, 86, 125, 11, 16, 72, 95, 27, 46, 59, 99, 60, 69, 91, 124, 87, 139, 168, 249, -1, 33, 18, 29, 32, 58, 71, 103, 19, 57, 44, 112, 70, 108, 90, 117, 47, 53, 94, 145, 66, 83, 76, 149, 65

Offset: 1

Author

N. J. A. Sloane, Apr 04 2022

Keywords

• sign

Comments

a(n) = -1 iff n = 2^k, k>0.

Links

• Rémy Sigrist, Table of n, a(n) for n = 1..10000
• Rémy Sigrist, PARI program

Crossrefs

Cf. A338833, A352572.

Programs

PARI

See Links section.