This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A109288 Semiprimes equal to p*q + 1, where p and q are distinct primes. 3
 15, 22, 34, 35, 39, 58, 86, 87, 94, 95, 119, 123, 134, 142, 143, 146, 159, 178, 202, 203, 206, 214, 215, 218, 219, 254, 299, 302, 303, 327, 335, 382, 394, 395, 446, 447, 454, 482, 502, 515, 527, 538, 543, 554, 566, 623, 634, 635, 695, 698, 699, 707, 718, 746 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS MATHEMATICA With[{nn=60}, Take[Select[Union[Times@@#+1&/@Subsets[Prime[Range[2nn]], {2}]], PrimeOmega[#]==2&], nn]] (* Harvey P. Dale, Apr 28 2018 *) PROG (PARI) for(i=1, 1000, if(bigomega(i)==2&&bigomega(i+1)==2&&issquare(i)==0, print1(i+1, ", "))) (Klasen) CROSSREFS Cf. A109287, A109289, A109290. Sequence in context: A038753 A006615 A114867 * A018889 A186525 A236107 Adjacent sequences:  A109285 A109286 A109287 * A109289 A109290 A109291 KEYWORD nonn AUTHOR Giovanni Teofilatto, Aug 20 2005 EXTENSIONS More terms from Lambert Klasen (lambert.klasen(AT)gmx.net), Aug 21 2005 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.

Last modified October 23 23:51 EDT 2019. Contains 328379 sequences. (Running on oeis4.)