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

1,1

Links

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

Example

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.

Prog

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

Crossrefs

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

Sequence in context: A349231 A141944 A281437 * A180550 A176134 A155844

Adjacent sequences: A319048 A319049 A319050 * A319052 A319053 A319054

Keyword

nonn

Author

Seiichi Manyama, Sep 08 2018

Status

approved