[seqfan] Re: is A110284 (4*prime-3 = square) the same as A112629 (2*semiprime-3=square)?

franktaw at netscape.net franktaw at netscape.net
Mon Jun 28 23:11:19 CEST 2010


Yes, they are the same.

An exception would have to be 2*(odd semiprime) - 3 = square. But 2 * 
(odd number) - 3 == 3 (mod 4), and thus cannot be a square.

Franklin T. Adams-Watters

-----Original Message-----
From: Richard Mathar <mathar at strw.leidenuniv.nl>

I am correcting A112629 (inserting 121) and get

9,25,49,121,169,289,625,841,961,1225,1681,1849,2401,3025,4489,5929,6889,1
0201,
11881,13225,14161,15625,17689,19321,20449,22801,24025,24649,25921,32041,3
2761,
39601,41209,44521,48841,49729,55225,57121,69169,76729,80089,82369,87025,9
0601,
94249,96721,104329,105625,108241,112225,113569,120409,124609,142129,14364
1,
148225,151321,165649,..

So far this is the same as A110284. Does this trend continue?
  




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