OFFSET
1,1
COMMENTS
p and q can be the same. [Harvey P. Dale, Jan 15 2012]
The terms are semiprimes of the form 4k + 1, and comprise only a portion of all such semiprimes, see A108181. - Richard R. Forberg, Aug 27 2013
LINKS
François Huppé, Table of n, a(n) for n = 1..10000 (First 1000 terms from T. D. Noe).
EXAMPLE
65 = 5 * 13. Note that 5 mod 4 = 1 and 13 mod 4 = 1, so 65 is a term.
MATHEMATICA
With[{prs=Select[Prime[Range[150]], Mod[#, 4]==1&]}, Take[Union[Times @@@ Tuples[prs, 2]], 60]] (* Harvey P. Dale, Jan 15 2012 *)
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Alford Arnold, Jul 26 2006, corrected Jun 24 2007
EXTENSIONS
Better definition from T. D. Noe, Sep 25 2007
STATUS
approved