A319051 Primes p such that none of p + 1, p + 2 and p + 3 are squarefree.

47, 97, 241, 349, 547, 773, 1249, 1447, 1663, 1847, 1861, 2347, 2887, 3049, 3547, 3607, 3623, 3697, 4111, 4373, 4597, 5237, 5273, 5749, 6173, 6857, 7549, 8467, 8647, 8719, 9161, 9349, 9547, 9749, 11149, 11321, 11447, 12049, 12473, 12689, 12823, 12941, 13147, 13291

Offset: 1

Author

Seiichi Manyama, Sep 08 2018

Keywords

• nonn

Examples

			48 = 2^4*3, 49 = 7^2 and 50 = 2*5^2. So 47 is a term.
98 = 2*7^2, 99 = 3^2*11 and 100 = 2^2*5^2. So 97 is a term.
		

Links

• Seiichi Manyama, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A000040, A049098, A257108, A319049, A319050.

Programs

PARI

forprime(p=2, 1e5, if(!issquarefree(p+1) && !issquarefree(p+2) && !issquarefree(p+3), print1(p", ")))