OFFSET
1,2
COMMENTS
If k is a term then either k or k+1 is a square. If k is in A005574 then k^2 is a term. - Amiram Eldar, Aug 08 2020
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
Jean-Marie De Koninck and Imre Kátai, On the coprimality of some arithmetic functions, Publications de l'Institut Mathématique, 2010 87(101):121-128.
EXAMPLE
8 is included because d(8) = 4 is relatively prime to d(9) = 3.
MATHEMATICA
Select[Range[1100], GCD[DivisorSigma[0, #], DivisorSigma[0, #+1]]==1&] (* Harvey P. Dale, Apr 04 2015 *)
PROG
(PARI) lista(nn) = {for(n=1, nn, if (gcd(numdiv(n), numdiv(n+1)) == 1, print1(n, ", "))); } \\ Michel Marcus, May 19 2014
CROSSREFS
KEYWORD
nonn
AUTHOR
Leroy Quet, Nov 11 2000
EXTENSIONS
Offset changed to 1 by Michel Marcus, May 20 2014
Name edited by Michel Marcus, Jan 12 2018
STATUS
approved