

A049098


Primes p such that p+1 is divisible by a square.


7



3, 7, 11, 17, 19, 23, 31, 43, 47, 53, 59, 67, 71, 79, 83, 89, 97, 103, 107, 127, 131, 139, 149, 151, 163, 167, 179, 191, 197, 199, 211, 223, 227, 233, 239, 241, 251, 263, 269, 271, 283, 293, 307, 311, 331, 337, 347, 349, 359, 367, 379, 383, 419, 431, 439, 443
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,1


COMMENTS

Numbers m such that A010051(m)*(1A008966(m+1)) = 1.  Reinhard Zumkeller, May 21 2009
A160696(a(n)) > 1.  Reinhard Zumkeller, May 24 2009


LINKS

T. D. Noe, Table of n, a(n) for n = 1..1000


EXAMPLE

31 is here because 32 is divisible by a square, 16.
101 is not here because 102=2*3*17 is squarefree.


MAPLE

with(numtheory): a := proc (n) if isprime(n) = true and issqrfree(n+1) = false then n else end if end proc: seq(a(n), n = 1 .. 500); # Emeric Deutsch, Jun 21 2009


MATHEMATICA

Select[Prime[Range[200]], !SquareFreeQ[#+1]&] (* Harvey P. Dale, Mar 27 2011 *)
Select[Prime[Range[200]], MoebiusMu[# + 1] == 0 &] (* Alonso del Arte, Oct 18 2011 *)


PROG

(Haskell)
a049098 n = a049098_list !! (n1)
a049098_list = filter ((== 0) . a008966 . (+ 1)) a000040_list
 Reinhard Zumkeller, Oct 18 2011
(PARI) forprime(p=2, 1e4, if(!issquarefree(p+1), print1(p", "))) \\ Charles R Greathouse IV, Oct 18 2011


CROSSREFS

Sequence in context: A136059 A156284 A045419 * A119992 A023249 A249682
Adjacent sequences: A049095 A049096 A049097 * A049099 A049100 A049101


KEYWORD

nonn,easy,nice


AUTHOR

Labos Elemer


STATUS

approved



