A395161 - OEIS

%I #11 Apr 20 2026 18:23:34

%S 1,3,12,14,16,19,22,37,40,47,54,55,56,71,73,74,76,84,86,96,102,103,

%T 105,107,108,110,111,118,119,123,129,130,133,161,165,174,179,184,185,

%U 188,195,200,213,219,240,254,255,272,273,292,299,330,334,340,354,355,356,358,359,370,386,388

%N k is a term if and only if, in the process described at A394915, there are no new point-like intersections after step k.

%C In other words, k is a term iff the line drawn at step k coincides with a line drawn at an earlier step.

%H Paolo Xausa, <a href="/A395161/b395161.txt">Table of n, a(n) for n = 1..1000</a>

%t A395161list[upto_] := With[{lines = MapIndexed[{#[[2]] - #[[1]], #[[1]] - (#[[2]] - #[[1]])*#2[[1]]} &, Partition[Prime[Range[upto+1]], 2, 1]]}, Table[If[k == 1 || MemberQ[lines[[;;k-1]], lines[[k]]], k, Nothing], {k, upto}]];

%t A395161list[500]

%Y Cf. A394915.

%Y Positions of zeros in A394225.

%K nonn

%O 1,2

%A _Paolo Xausa_, Apr 14 2026