0,4

Motivation: A294673(n), which is always <= 2n+1, equals n in most cases. This sequence abstracts out that commonality to leave a cleaner signal.

Table of n, a(n) for n=0..77.

(PARI) a(n) = (2*n+1) - znorder(Mod(if(n%2, 2, -2), 4*n+3)); \\ Michel Marcus, May 26 2018

Cf. A294673.

Sequence in context: A305223 A316801 A143044 * A127775 A210953 A254280

Adjacent sequences: A305148 A305149 A305150 * A305152 A305153 A305154

nonn

P. Michael Hutchins, May 26 2018

approved