A345419 - OEIS

%I #11 Jul 01 2021 23:40:47

%S 1,0,2,-2,4,-4,6,-6,8,10,-10,-12,14,-14,16,18,20,-20,-22,24,-24,-26,

%T 28,30,-32,34,-34,36,-36,38,-42,44,46,-46,50,-50,-52,-54,56,58,60,-60,

%U 64,-64,66,-66,-70,-74,76,-76,78,80,-80,84,86,88,90,-90,-92,94,-94,98,-102,104,-104

%N Row 2 of array in A345417.

%o (Python)

%o from sympy.core.numbers import igcdex

%o from sympy import prime

%o def A345419(n): return igcdex(3, prime(n))[0] # _Chai Wah Wu_, Jul 01 2021

%Y Cf. A345417-A345422.

%K sign

%O 1,3

%A _N. J. A. Sloane_, Jun 19 2021