A395087 - OEIS

A395087

a(n) is the number of vertices of the convex hull of the finite point set {(k, prime(k)), k = 1..n} (where prime(k) denotes the k-th prime number).

%I #10 Apr 14 2026 08:42:36

%S 1,2,3,3,4,5,5,5,5,6,6,6,6,6,6,6,6,7,7,7,7,7,7,8,9,8,8,8,9,8,8,9,8,9,

%T 9,9,9,8,9,8,8,9,9,10,9,10,9,9,10,11,11,10,11,11,10,10,10,10,10,10,11,

%U 10,11,11,12,12,11,11,11,12,12,12,13,11,11,11,11

%N a(n) is the number of vertices of the convex hull of the finite point set {(k, prime(k)), k = 1..n} (where prime(k) denotes the k-th prime number).

%H Rémy Sigrist, <a href="/A395087/b395087.txt">Table of n, a(n) for n = 1..10000</a>

%H Rémy Sigrist, <a href="/A395087/a395087.png">Illustration of a(36)</a>

%H Rémy Sigrist, <a href="/A395087/a395087.gp.txt">PARI program</a>

%e See illustration in Links section.

%o (PARI) \\ See Links section.

%Y Cf. A246033, A395094, A395098, A395113.

%K nonn

%O 1,2

%A _Rémy Sigrist_, Apr 11 2026