|
Search: id:A164521
|
|
| |
|
| 3373, 753569, 2146687, 3048623, 6539201, 8120599, 10218311, 17373977, 18609623, 19034161, 32461757, 44738873, 59776469, 69426529, 72511711, 77854481, 88121123, 116930167, 133432829, 299418307, 338608871, 413493623, 458314009, 679151437
(list; graph; listen)
|
|
|
OFFSET
|
1,1
|
|
|
COMMENT
|
Primes p such that p+2 is the cube of a square-free semiprime, i.e., such that
p+2 = q^3*r^3 where q and r are two distinct primes.
|
|
EXAMPLE
|
3373+2 = 3375 = 3^3*5^3. 753569+1 = 753571 = 7^3*13^3.
|
|
MATHEMATICA
|
f3[n_]:=FactorInteger[n][[1, 2]]==3&&Length[FactorInteger[n]]==2&&FactorInteger[n][[2, 2]]==3; lst={}; Do[p=Prime[n]; If[f3[p+2], AppendTo[lst, p]], {n, 4, 4*9!}]; lst
|
|
CROSSREFS
|
Cf. A006881, A056899, A144953, A164517, A164518, A164519, A164520
Sequence in context: A139778 A139779 A052357 this_sequence A114769 A013803 A013876
Adjacent sequences: A164518 A164519 A164520 this_sequence A164522 A164523 A164524
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Vladimir Orlovsky (4vladimir(AT)gmail.com), Aug 14 2009
|
|
EXTENSIONS
|
Edited and examples corrected by R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Aug 21 2009
|
|
|
Search completed in 0.002 seconds
|
