|
Search: id:A061400
|
|
|
| A061400 |
|
Primes p such that there is no square-free number between p and the next prime. |
|
+0
6
|
|
| 2, 3, 11, 17, 59, 71, 97, 107, 149, 179, 191, 197, 227, 239, 269, 311, 347, 349, 419, 431, 521, 599, 659, 809, 827, 881, 1019, 1031, 1049, 1061, 1091, 1151, 1277, 1319, 1427, 1447, 1451, 1487, 1607, 1619, 1663, 1667, 1787, 1871, 1931, 1949, 1997, 2027, 2087
(list; graph; listen)
|
|
|
OFFSET
|
1,1
|
|
|
COMMENT
|
Primes in sequence A112925. - Leroy Quet Oct 06 2005
|
|
LINKS
|
Harry J. Smith, Table of n, a(n) for n=1,...,1000
Leroy Quet, Home Page (listed in lieu of email address)
|
|
EXAMPLE
|
Between 71 and 73 the only composite is 72=2.2.2.3.3, not square-free. Between 97 and 101, 98, 99, 100 have square divisors.
|
|
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 (deutsch(AT)duke.poly.edu), Oct 14 2005
|
|
PROGRAM
|
(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 ) } [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), Jul 22 2009]
|
|
CROSSREFS
|
Cf. A005117, A013929.
Cf. A112925, A112926, A112928, A112929, A112930.
Sequence in context: A051078 A051096 A051090 this_sequence A090474 A024861 A025101
Adjacent sequences: A061397 A061398 A061399 this_sequence A061401 A061402 A061403
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Labos E. (labos(AT)ana.sote.hu), Jun 07 2001
|
|
EXTENSIONS
|
Edited by N. J. A. Sloane (njas(AT)research.att.com), Aug 23 2008 at the suggestion of R. J. Mathar
|
|
|
Search completed in 0.002 seconds
|
