login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A319051 Primes p such that none of p + 1, p + 2 and p + 3 are squarefree. 2
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 (list; graph; refs; listen; history; text; internal format)
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: A044566 A141944 A281437 * A180550 A176134 A155844

Adjacent sequences:  A319048 A319049 A319050 * A319052 A319053 A319054

KEYWORD

nonn

AUTHOR

Seiichi Manyama, Sep 08 2018

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified November 17 16:01 EST 2019. Contains 329236 sequences. (Running on oeis4.)