A175216 The first nonprimes after the primes.

4, 4, 6, 8, 12, 14, 18, 20, 24, 30, 32, 38, 42, 44, 48, 54, 60, 62, 68, 72, 74, 80, 84, 90, 98, 102, 104, 108, 110, 114, 128, 132, 138, 140, 150, 152, 158, 164, 168, 174, 180, 182, 192, 194, 198, 200, 212, 224, 228, 230, 234, 240, 242, 252, 258, 264, 270, 272

Offset: 1

Author

Jaroslav Krizek, Mar 06 2010

Keywords

• nonn
• easy

Comments

Essentially the same as A135731, A055670, A028815 and A008864. [R. J. Mathar, Mar 13 2010]

Links

• G. C. Greubel, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A000040, A008864, A028815, A055670, A135731.

Programs

Magma

[n eq 1 select 4 else NthPrime(n) +1: n in [1..100]]; // G. C. Greubel, Aug 06 2024

Mathematica

Table[Prime[n] +1 +Boole[n==1], {n,100}] (* G. C. Greubel, Aug 06 2024 *)

SageMath

def A175216(n): return nth_prime(n) +1 +int(n==1)
[A175216(n) for n in range(1,101)] # G. C. Greubel, Aug 06 2024

Formula

a(1) = 4, for n >= 2, a(n) = A008864(n) = A000040(n) + 1.