A345419 Row 2 of array in A345417.

1, 0, 2, -2, 4, -4, 6, -6, 8, 10, -10, -12, 14, -14, 16, 18, 20, -20, -22, 24, -24, -26, 28, 30, -32, 34, -34, 36, -36, 38, -42, 44, 46, -46, 50, -50, -52, -54, 56, 58, 60, -60, 64, -64, 66, -66, -70, -74, 76, -76, 78, 80, -80, 84, 86, 88, 90, -90, -92, 94, -94, 98, -102, 104, -104

Offset

1,3

Links

Table of n, a(n) for n=1..65.

Prog

(Python)
from sympy.core.numbers import igcdex
from sympy import prime
def A345419(n): return igcdex(3, prime(n))[0] # Chai Wah Wu, Jul 01 2021

Crossrefs

Cf. A345417-A345422.

Sequence in context: A137501 A308767 A353504 * A285999 A005186 A259881

Adjacent sequences: A345416 A345417 A345418 * A345420 A345421 A345422

Keyword

sign

Author

N. J. A. Sloane, Jun 19 2021

Status

approved