A373052 - OEIS

A373052

Lexicographically earliest sequence of positive integers such that no three terms a(j), a(j+k), a(j+2k) (for any j and k) form a weakly decreasing arithmetic progression.

%I #15 May 26 2024 08:21:00

%S 1,1,2,1,1,2,2,3,3,1,1,2,1,1,2,2,3,3,2,3,3,4,4,5,4,4,5,1,3,2,4,1,1,2,

%T 1,3,2,4,2,5,1,2,2,1,3,3,4,3,4,5,2,4,3,5,5,6,3,4,3,6,4,4,5,5,4,5,5,6,

%U 6,7,6,6,7,7,5,8,6,8,6,7,7,2,7,7,2,8

%N Lexicographically earliest sequence of positive integers such that no three terms a(j), a(j+k), a(j+2k) (for any j and k) form a weakly decreasing arithmetic progression.

%H Rémy Sigrist, <a href="/A373052/a373052.gp.txt">PARI program</a>.

%H Neal Gersh Tolunsky, <a href="/A373052/a373052.png">Graph of first 400000 terms</a>.

%o (PARI) \\ See Links section.

%Y Cf. A229037, A309890, A100480, A373010, A361933.

%K nonn

%O 1,3

%A _Neal Gersh Tolunsky_, May 20 2024