OFFSET
1,1
COMMENTS
Primes in sequence A112925. - Leroy Quet, Oct 06 2005
LINKS
Harry J. Smith, Table of n, a(n) for n = 1..1000
EXAMPLE
Between 71 and 73, the only composite is 72 = 2*2*2*3*3, not squarefree. Each of the integers between 97 and 101 has at least one squared divisor.
MAPLE
with(numtheory): a:=proc(n) local p, B, j: p:=ithprime(n): B:={}: for j from 1 to p-1 do if abs(mobius(j))>0 then B:=B union {j} else B:=B fi od: B[nops(B)] end: A:=[seq(a(m), m=1..400)]: b:=proc(k) if isprime(A[k])=true then A[k] else fi end: seq(b(i), i=1..400); # Emeric Deutsch, Oct 14 2005
MATHEMATICA
Select[Prime@ Range@ 310, Count[Range[# + 1, NextPrime@ # - 1], k_ /; SquareFreeQ@ k] == 0 &] (* Michael De Vlieger, Feb 19 2017 *)
PROG
(PARI) { n=0; p=2; forprime (q=3, 109621, c=0; for (i=p+1, q-1, c+=issquarefree(i); if (c, break)); if (c==0, write("b061400.txt", n++, " ", p)); p=q ) } \\ Harry J. Smith, Jul 22 2009
CROSSREFS
KEYWORD
nonn
AUTHOR
Labos Elemer, Jun 07 2001
EXTENSIONS
Edited by N. J. A. Sloane, Aug 23 2008 at the suggestion of R. J. Mathar
STATUS
approved